Clinical chorioamnionitis at term VI: acute chorioamnionitis and funisitis according to the presence or absence of microorganisms and inflammation in the amniotic cavity
-
Roberto Romero
,
Piya Chaemsaithong
Abstract
Objective: Neonates born to mothers with clinical chorioamnionitis at term are at an increased risk of infection. Acute subchorionitis, chorioamnionitis, and funisitis are considered placental histologic features consistent with acute inflammation according to the Society for Pediatric Pathology. The objectives of this study were to examine the performance of placental histologic features in the identification of: 1) microbial-associated intra-amniotic inflammation (intra-amniotic infection); and 2) fetal inflammatory response syndrome (FIRS).
Methods: This retrospective cohort study included women with the diagnosis of clinical chorioamnionitis at term (n=45), who underwent an amniocentesis to determine: 1) the presence of microorganisms using both cultivation and molecular biologic techniques [polymerase chain reaction (PCR) with broad range primers]; and 2) interleukin (IL)-6 concentrations by enzyme-linked immunosorbent assay (ELISA). The diagnostic performance (sensitivity, specificity, accuracy, and likelihood ratios) of placental histologic features consistent with acute inflammation was determined for the identification of microbial-associated intra-amniotic inflammation and FIRS.
Results: 1) The presence of acute histologic chorioamnionitis and funisitis was associated with the presence of proven intra-amniotic infection assessed by amniotic fluid analysis; 2) funisitis was also associated with the presence of FIRS; 3) the negative predictive value of acute funisitis ≥stage 2 for the identification of neonates born to mothers with intra-amniotic infection was <50%, and therefore, suboptimal to exclude fetal exposure to bacteria in the amniotic cavity; and 4) acute funisitis ≥stage 2 had a negative predictive value of 86.8% for the identification of FIRS in a population with a prevalence of 20%.
Conclusion: Acute histologic chorioamnionitis and funisitis are associated with intra-amniotic infection and the presence of FIRS. However, current pathologic methods have limitations in the identification of the fetus exposed to microorganisms present in the amniotic cavity. Further studies are thus required to determine whether molecular markers can enhance the performance of placental pathology in the identification of neonates at risk for neonatal sepsis.
Introduction
Clinical chorioamnionitis is a heterogeneous syndrome [1] characterized by maternal fever accompanied by at least two of the following signs: maternal or fetal tachycardia, maternal leukocytosis, uterine tenderness, or foul-smelling amniotic fluid [2–14]. This syndrome is associated with proven intra-amniotic infection in almost 60% of cases, and is a major risk factor for neonatal sepsis [12, 15–23]. The rapid and accurate diagnosis of maternal intra-amniotic infection is important to guide the management of neonates exposed to intrapartum fever [24–34]. The gold standard for the diagnosis of intra-amniotic infection is amniotic fluid analysis with the use of cultivation and molecular microbiologic techniques to identify the presence of bacteria [35–52] and to assess the inflammatory response [13, 35–37, 53–59].
When information about the amniotic fluid microbiology and inflammatory state is not available, pediatricians must rely on clinical risk factors (e.g., maternal fever, rupture of membranes, etc.) [26–28, 60], signs of neonatal sepsis and laboratory tests, such as neonatal white blood cell and differential counts [61–80], immature to mature ratio of neutrophils [77, 80–83], interleukin (IL)-6 [84–118], IL-8 [81, 91, 100, 101, 104, 106, 109, 113, 119], C-reactive protein (CRP) [68–70, 72, 78, 103, 104, 113, 118, 120–125], procalcitonin [118, 123, 124, 126–128], blood [26, 30, 82, 129–134], and cerebro-spinal fluid cultures [135–144], as well as other biomarkers. Despite intensive investigation, the accurate identification of early-onset sepsis in neonatology remains a conundrum [26–28, 32, 34, 145].
Examination of the placenta, the largest human biopsy, can provide information about fetal exposure to intra-amniotic inflammation or infection [146–169]. Chorionitis and acute histologic chorioamnionitis are histologic lesions that represent a maternal response to inflammatory stimuli in the amniotic cavity, such as bacteria, viruses and fungi, or non-infectious insults, such as danger signals (alarmins resulting from cell stress, apoptosis, and pyroptosis) [156, 158, 163, 170–173]. Inflammation of the umbilical cord or chorionic vessels represents a fetal response and is indicative of a fetus’s exposure to inflammatory stimuli before birth [154].
As early as 1959, Benirschke proposed that the examination of the umbilical cord using a frozen section could be a rapid and accurate method to identify newborns exposed to infection in utero [146]. Decades later, this idea has been revisited [174–176]. However, a major limitation of all clinical studies performed to date in patients with clinical chorioamnionitis at term is that the presence of bacteria in the amniotic cavity remains unknown, and therefore, accurate ascertainment of intra-amniotic infection is not feasible. The objective of the current study was to examine the diagnostic performance of placental histologic features of acute inflammation in the identification of: 1) microbial-associated intra-amniotic inflammation (also termed intra-amniotic infection), and 2) fetal inflammatory response syndrome (FIRS). The latter outcome was selected because there is evidence that both FIRS [98, 177–191] and neonatal systemic inflammation [192–209] are associated with adverse neonatal and infant outcomes.
Materials and methods
This retrospective cohort study included women with the diagnosis of clinical chorioamnionitis at term, who underwent an amniocentesis to identify microorganisms in the amniotic cavity. Patients were identified by searching the clinical database and Bank of Biological Samples of Wayne State University, the Detroit Medical Center, and the Perinatology Research Branch (NICHD/NIH/DHHS). The criteria for entry were: 1) singleton gestation, 2) gestational age of ≥37 weeks, 3) sufficient amniotic fluid obtained by transabdominal amniocenteses for molecular microbiologic studies, and 4) absence of fetal malformations. These patients were included in prior studies, which provide a detailed description of sample collection, microbiological studies, and determination of amniotic fluid IL-6 concentrations and other cytokines [1, 3, 9–11].
All patients provided written informed consent. The use of biological specimens as well as clinical and ultrasound data for research purposes was approved by the Institutional Review Boards of NICHD, Wayne State University, and Sótero del Río Hospital, Santiago, Chile.
Clinical definitions
Microbial invasion of the amniotic cavity was defined according to the results of amniotic fluid culture and PCR/ESI-MS (broad-range PCR coupled with electrospray ionization mass spectrometry) (Ibis® Technology, Athogen, Carlsbad, CA, USA) [1, 45–47, 210]. Microbial-associated intra-amniotic inflammation (also termed intra-amniotic infection) was diagnosed when microorganisms were identified in the amniotic fluid using cultivation or molecular microbiologic techniques and elevated amniotic fluid IL-6 concentrations (≥2.6 ng/mL), as described in detail elsewhere [1, 13, 35–37, 39, 50, 53, 54, 56–59, 211–213].
Clinical chorioamnionitis was diagnosed by the presence of maternal fever (temperature >37.8°C) accompanied by two or more of the following criteria: 1) maternal tachycardia (heart rate >100 beats/min), 2) uterine tenderness, 3) foul-smelling amniotic fluid, 4) fetal tachycardia (heart rate >160 beats/min), and 5) maternal leukocytosis (leukocyte count >15,000 cells/mm3) [2, 4–8, 12, 214]. FIRS was diagnosed when umbilical cord plasma IL-6 concentrations were >11 pg/mL [178, 187–189, 215–217].
Placental pathology
Tissue samples were obtained from each placenta – one roll from the chorioamniotic membranes and one from the umbilical cord. Two sections were taken from both the chorionic and basal plates. Tissues were formalin-fixed and embedded in paraffin. Five-micrometer-thick sections of tissue blocks were stained with hematoxylin and eosin, and the slides were examined by perinatal pathologists masked to clinical outcomes.
Histopathological changes of the placenta were defined according to the diagnostic criteria proposed by the Perinatal Section of the Society for Pediatric Pathology [156]. Histologic features associated with acute inflammation are acute subchorionitis, acute histologic chorioamnionitis (maternal response), and funisitis/acute chorionic vasculitis (fetal response). The definition and staging of acute histologic chorioamnionitis and acute funisitis are described below.
Placental histologic features consistent with acute inflammation (maternal response) were diagnosed based on the presence of inflammatory cells in the chorionic plate and/or in the chorioamniotic membranes [156].
Stage 1 (acute subchorionitis/acute chorionitis): accumulation of neutrophils in the subchorionic zone and/or in the chorionic trophoblast layer of the extraplacental membranes.
Stage 2 (acute chorioamnionitis): more than a few scattered neutrophils in the chorionic plate and membranous connective tissues and/or in the amnion.
Stage 3 (necrotizing chorioamnionitis): marked neutrophilic infiltrate with degenerating neutrophils (karyorrhexis), thickened eosinophilic amniotic basement membrane, and focal amniotic epithelial necrosis.
Acute funisitis was diagnosed by the presence of neutrophils in the wall of the umbilical vessels and/or the Wharton’s jelly, also using previously reported criteria [98, 154, 156, 157, 218–220].
Stage 1 (acute chorionic vasculitis/umbilical phlebitis/chorionic vasculitis): neutrophils are identified in the wall of any chorionic plate vessel or in the umbilical vein (few neutrophils are usually present in the Wharton’s jelly, but without aggregates or concentric bands of inflammatory cells).
Stage 2 (umbilical arteritis): neutrophils are seen in one or both of the umbilical arteries and/or in the umbilical vein.
Stage 3 (necrotizing funisitis): presence of neutrophils, cellular debris, and/or mineralization in a concentric band, ring, or halo around one or more umbilical vessel(s).
Statistical analysis
The Kolmogorov-Smirnov test was used to test whether data were normally distributed. Chi-square and Fisher’s exact tests were used for comparisons of proportions. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and likelihood ratios (+/−) were all calculated for the identification of microbial-associated intra-amniotic inflammation and FIRS. Statistical analysis was performed using SPSS 19 (IBM Corp, Armonk, NY, USA). A P-value <0.05 was considered statistically significant.
Results
Clinical characteristics of the study population
The descriptive characteristics of the study population stratified by the presence or absence of microbial-associated intra-amniotic inflammation (intra-amniotic infection) were previously reported [3]. Microorganisms most frequently identified in the amniotic cavity were Ureaplasma spp. and Gardnerella vaginalis [1]. Briefly, patients with clinical chorioamnionitis at term with microbial-associated intra-amniotic inflammation had a significantly higher median amniotic fluid white blood cell count, amniotic fluid IL-6, and umbilical cord plasma IL-6 concentration than those without microbial-associated intra-amniotic inflammation (P<0.001, P<0.001, and P=0.03, respectively) [3]. The frequencies of FIRS and acute inflammatory lesions of the placenta were also significantly greater in patients with clinical chorioamnionitis at term with microbial-associated intra-amniotic inflammation than in those without microbial-associated intra-amniotic inflammation [FIRS: 36% (9/25) vs. 5% (1/20), P=0.03; and acute inflammatory lesions of the placenta: 70.8% (17/24) vs. 25% (5/20), P=0.02] [3].
The frequency of neonates with FIRS was 22.2% (10/45). Among them, 90% (9/10) and 66.7% (6/9) were born to mothers with intra-amniotic infection and with placental histologic lesions consistent with acute amniotic fluid infection respectively, [acute subchorionitis/histologic chorioamnionitis (n=5) or inflammation of the umbilical cord (n=5)] (Table 1). Among neonates with FIRS, whose mothers had placental histologic features consistent with acute inflammation, 83% (5/6) had stage 2 acute histologic chorioamnionitis/funisitis (Table 1). The descriptions of clinical characteristics, bacteria isolated from the amniotic cavity, amniotic fluid and umbilical cord plasma IL-6 concentrations, as well as placental histologic lesions in mothers whose neonates had FIRS, are shown in Table 1.
Clinical characteristics, amniotic fluid interleukin-6 concentrations, microorganisms identified in the amniotic cavity, and placental histologic features consistent with acute inflammation in mothers whose neonates have fetal inflammatory response syndrome (FIRS) (n=10/45; 22.2%).
| No. | Organisms identified by cultivation | Organisms identified by PCR/ESI-MS | Microbial-associated intra-amniotic inflammation (intra-amniotic infection) | GA at delivery (weeks) | Amniotic fluid IL-6 concentration (ng/mL) | Umbilical cord plasma IL-6 concentration (pg/mL) | Maternal response to acute inflammation | Fetal response to acute inflammation |
|---|---|---|---|---|---|---|---|---|
| 1. | Peptostreptococcus spp. | Gardnerella vaginalis Abiotrophia defectiva | Yes | 41+1 | 97.1 | 170.85 | No | Umbilical arteritis |
| 2. | Fusobacterium spp. | Fusobacterium nucleatum/periodonticum | Yes | 37+4 | 118.35 | 103.01 | Acute chorioamnionitis | Umbilical arteritis |
| 3. | Ureaplasma urealyticum Streptococcus agalactiae | Ureaplasma urealyticum Gardnerella vaginalis | Yes | 40+5 | 83.19 | 14.13 | Acute chorioamnionitis | Umbilical arteritis |
| 4. | No | No | No | 40+3 | 109.19 | 12.14 | Acute chorioamnionitis | Umbilical arteritis |
| 5. | Ureaplasma urealyticum | Firmicute (Lactobacillus) | Yes | 41+4 | 14.12 | 101.09 | No | No |
| 6. | Ureaplasma urealyticum Enterococcus spp. Gardnerella vaginalis | Peptostreptococcus anaerobius Ureaplasma urealyticum Gardnerella vaginalis | Yes | 41+1 | 19.94 | 52.84 | No | No |
| 7. | Staphylococcus agalactiae Staphylococcus aureus | Staphylococcus agalactiae | Yes | 40+4 | 32.82 | 31.67 | Acute chorioamnionitis | Umbilical phlebitis/chorionic vasculitis |
| 8. | Staphylococcus agalactiae | Staphylococcus agalactiae | Yes | 39+4 | 10.45 | 14.78 | No | No |
| 9. | No | Acinetobacter spp. Pseudomonas aerunginosa | Yes | 40+4 | 18.41 | 12.38 | Acute subchorionitis/chorionitis | No |
| 10. | Mycoplasma hominis | Propionibacterium acnes | Yes | 38+4 | 74.08 | 32.99 | N/Aa | N/Aa |
aN/A=A placental pathology report was not available for 1 patient, PCR ESI/MS=broad-range PCR coupled with electrospray ionization mass spectrometry, GA=gestational age, IL=interleukin.
Microbial-associated intra-amniotic inflammation defined by the presence of bacteria in the amniotic cavity and intra-amniotic inflammation (IL-6 ≥2.6 ng/mL); fetal inflammatory response is defined by a concentration of umbilical cord plasma IL-6 >11 pg/mL.
Acute subchorionitis/chorionitis=maternal response to acute inflammation stage 1, Acute chorioamnionitis=maternal response to acute inflammation stage 2, Necrotizing chorioamnionitis and subacute chorioamnionitis=maternal response to acute inflammation stage 3, Umbilical phlebitis/chorionic vasculitis=acute funisitis stage 1, Umbilical arteritis=acute funisitis stage 2, Necrotizing funisitis=acute funisitis stage 3.
Overall, 33% (15/45) of neonates born to mothers with clinical chorioamnionitis had suspected neonatal sepsis. Among these neonates, 53.3% (8/15) and 20% (3/15) were exposed to intra-amniotic infection and intra-amniotic inflammation without detectable bacteria, respectively. The remaining 26.7% (4/15) were born to mothers who had no intra-amniotic inflammation. All neonates with suspected neonatal sepsis (diagnosis based on clinical signs and laboratory findings) had negative blood cultures for microorganisms.
Diagnostic performance
The diagnostic performance of placental histologic features consistent with acute inflammation for the identification of microbial-associated intra-amniotic inflammation (also termed intra-amniotic infection) is shown in Table 2. The sensitivity of placental histologic features of acute inflammation ranged from 16.7% to 70.8%. Specifically, acute histologic chorioamnionitis and funisitis ≥stage 2 had sensitivities of 25% (6/24) and 16.7% (4/24), respectively (Table 2). The PPV or NPV of placental histologic features associated with acute inflammation was fair (PPV: 60%–73.9%; NPV: 47.1%–66.7%) (Table 2). Overall, the accuracy of placental histologic features of acute inflammation for the identification of microbial-associated intra-amniotic inflammation only ranged from 50% to 70% (Table 2).
The diagnostic performance of placental histologic features consistent with acute inflammation for the identification of intra-amniotic infection (microbial-associated intra-amniotic inflammation) in patients with clinical chorioamnionitis at term (n=25/45; 55.56%).a
| Sensitivity (%) | Specificity (%) | Positive likelihood ratio (95% CI) | Negative likelihood ratio (95% CI) | Positive predictive value (%) | Negative predictive value (%) | Accuracy | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| % (n) | 95% CI | % (n) | 95% CI | % (n) | 95% CI | % (n) | 95% CI | ||||
| Acute subchorionitis, chorioamnionitis (n=22/44) | 66.7% (16/24) | (44.7–84.3) | 70.0% (14/20) | (45.7–88.0) | 2.2 (1.0–4.6) | 0.5 (0.3–0.9) | 72.7% (16/22) | (49.8–89.2) | 63.6% (14/22) | (40.7–82.8) | 68.2% (30/44) |
| Acute funisitis (n=13/44) | 33.3% (8/24) | (15.7–55.3) | 70.0% (14/20) | (45.7–91.3) | 1.3 (0.5–3.4) | 0.9 (0.6–1.3) | 61.5% (8/13) | (31.6–86.0) | 48.4% (15/31) | (30.2–66.9) | 52.3% (23/44) |
| Acute inflammatory histologic features of the placenta (n=23/44) | 70.8% (17/24) | (48.9–87.3) | 71.4% (15/21) | (47.8–88.0) | 2.4 (1.2–4.8) | 0.4 (0.2–0.8) | 73.9% (17/23) | (51.6–89.7) | 66.7% (17/21) | (43.0–85.4) | 70.5% (31/44) |
| Acute histologic chorioamnionitis ≥stage 2 (n=10/44) | 25.0% (6/24) | (9.8–46.7) | 80.0% (16/20) | (56.3–94.1) | 1.3 (0.4–3.8) | 0.9 (0.7–1.3) | 60.0% (6/10) | (26.4–87.6) | 47.1% (16/34) | (29.8–64.9) | 50% (22/44) |
| Acute funisitis ≥stage 2 (n=6/44) | 16.7% (4/24) | (4.8–37.4) | 90.0% (18/20) | (68.3–98.5) | 1.7 (0.3–8.2) | 0.9 (0.7–1.2) | 66.7% (4/6) | (22.7–94.7) | 47.4% (18/38) | (30.9–64.2) | 50% (22/44) |
aA placental pathology report was not available for 1 patient.
CI=confidence interval, intra-amniotic infection (microbial-associated intra-amniotic inflammation) is defined by the presence of bacteria in the amniotic cavity and intra-amniotic inflammation (IL-6≥2.6 ng/mL).
Acute subchorionitis/chorionitis=maternal response to acute inflammation stage 1, Acute chorioamnionitis=maternal response to acute inflammation stage 2, Necrotizing chorioamnionitis and subacute chorioamnionitis=maternal response to acute inflammation stage 3, Umbilical phlebitis/chorionic vasculitis=acute funisitis stage 1, Umbilical arteritis=acute funisitis stage 2, Necrotizing funisitis=acute funisitis stage 3.
Acute inflammatory histologic features of the placenta: acute subchorionitis, chorioamnionitis and/or acute funisitis.
The diagnostic performance of placental histologic lesions for the identification of FIRS is displayed in Table 3. The sensitivity and specificity ranged from 44.4% to 66.7% and 51.4% to 94.3%, respectively. Acute funisitis ≥stage 2 had the highest specificity (94.3%) followed by acute histologic chorioamnionitis ≥stage 2 (82.9%) when compared to other placental histologic lesions (Table 3). All placental histologic features had an NPV above 80%; however, the PPV ranged from 22.7% to 66.7% (Table 3). Acute funisitis ≥stage 2 had a positive likelihood ratio of 7.8 for the identification of FIRS.
The diagnostic performance of placental histologic features consistent with acute inflammation for the identification of fetal inflammatory response syndrome (FIRS) in patients with clinical chorioamnionitis at term (n=9/45; 20%).a
| Sensitivity (%) | Specificity (%) | Positive likelihood ratio (95% CI) | Negative likelihood ratio (95% CI) | Positive predictive value (%) | Negative predictive value (%) | Accuracy | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| % (n) | 95% CI | % (n) | 95% CI | % (n) | 95% CI | % (n) | 95% CI | ||||
| Acute subchorionitis, chorioamnionitis (n=22/44) | 55.6% (5/9) | (21.4–86.0) | 51.4% (18/35) | (34.0–68.6) | 1.1 (0.6–2.3) | 0.9 (0.4–1.9) | 22.7% (5/22) | (7.9–45.4) | 81.8% (18/22) | (59.7–94.7) | 52.3% (23/44) |
| Acute funisitis (n=13/44) | 55.6% (5/9) | (21.4–86.0) | 77.1% (27/35) | (59.9–89.6) | 2.4 (1.1–5.7) | 0.6 (0.3–1.2) | 38.5% (5/13) | (14.0–68.4) | 87.1% (27/31) | (70.2–96.3) | 72.7% (32/44) |
| Acute inflammatory histologic features of the placenta (n=23/44) | 66.7% (6/9) | (30.1–92.1) | 51.4% (18/35) | (34.0–68.6) | 1.4 (0.8–2.4) | 0.7 (0.2–1.7) | 26.1% (6/23) | (10.3–48.4) | 85.7% (18/21) | (63.6–96.8) | 54.5% (24/44) |
| Acute histologic chorioamnionitis ≥stage 2 (n=10/44) | 44.4% (4/9) | (13.9–78.6) | 82.9% (29/35) | (66.3–93.4) | 2.6 (0.9–7.3) | 0.7 (0.4–1.2) | 40.0% (4/10) | (12.4–73.6) | 85.3% (29/34) | (68.9–94.9) | 75.% (33/44) |
| Acute funisitis ≥stage 2 (n=6/44) | 44.4% (4/9) | (13.9–78.6) | 94.3% (33/35) | (80.8–99.1) | 7.8 (1.7–35.9) | 0.6 (0.3–1.1) | 66.7% (4/6) | (22.7–94.7) | 86.8% (33/38) | (71.9–95.5) | 72.7% (32/44) |
aA placental pathology report was not available for 1 patient.
CI=confidence interval, FIRS=fetal inflammatory response syndrome is defined by umbilical cord interleukin-6 concentration >11 pg/mL.
Acute subchorionitis/chorionitis=maternal response to acute inflammation stage 1, Acute chorioamnionitis=maternal response to acute inflammation stage 2, Necrotizing chorioamnionitis and subacute chorioamnionitis=maternal response to acute inflammation stage 3, Umbilical phlebitis/chorionic vasculitis=acute funisitis stage 1, Umbilical arteritis=acute funisitis stage 2, Necrotizing funisitis=acute funisitis stage 3.
Acute inflammatory histologic features of the placenta: acute subchorionitis, chorioamnionitis and/or acute funisitis.
The diagnostic indices of acute inflammatory histologic features of the placenta for the identification of intra-amniotic inflammation are shown in Table 4. The sensitivity and NPV for such placental histologic features ranged from 14.7% to 61.7%, and 23.7%–38.1%, respectively. The overall accuracy was <70% in the identification of intra-amniotic inflammation (Table 4).
The diagnostic performance of placental histologic features consistent with acute inflammation for the identification of intra-amniotic inflammation in patients with clinical chorioamnionitis at term (n=35/45; 77.8%).a
| Sensitivity (%) | Specificity (%) | Positive likelihood ratio (95% CI) | Negative likelihood ratio (95% CI) | Positive predictive value (%) | Negative predictive value (%) | Accuracy | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| % (n) | 95% CI | % (n) | 95% CI | % (n) | 95% CI | % (n) | 95% CI | ||||
| Acute subchorionitis, chorioamnionitis (n=22/44) | 58.8% (20/34) | (40.7–75.3) | 80% (8/10) | (44.4–98.9) | 2.9 (0.8–10.5) | 0.5 (0.3–0.9) | 90.9% (20/22) | (70.8–98.6) | 36.4% (8/22) | (17.2–59.3) | 63.6% (28/44) |
| Acute funisitis (n=13/44) | 32.4% (11/34) | (17.4–50.5) | 80% (8/10) | (44.4–96.9) | 1.6 (0.4–6.1) | 0.9 (0.6–1.3) | 84.6% (11/13) | (54.5.–97.6) | 25.8% (8/31) | (11.9–44.6) | 43.2% (19/44) |
| Acute inflammatory histologic features of the placenta (n=23/44) | 61.8% (21/34) | (43.6–77.8) | 80% (8/10) | (44.4–96.8) | 3.1 (0.9–10.9) | 0.5 (0.3–0.8) | 91.3% (21/23) | (71.9–98.7) | 38.1% (8/21) | (18.2–61.6) | 65.9% (29/44) |
| Acute histologic chorioamnionitis ≥stage 2 (n=10/44) | 23.5% (8/34) | (10.8–41.2) | 80% (8/10) | (44.4–96.9) | 1.2 (0.3–4.7) | 0.9 (0.7–1.4) | 80.0% (8/10) | (44.4–96.9) | 25.5% (8/34) | (10.8–41.2) | 36.4% (16/44) |
| Acute funisitis≥stage 2 (n=6/44) | 14.7 % (5/34) | (5.0–31.1) | 90% (9/10) | (55.5–98.3) | 1.5 (0.2–11.2) | 0.95 (0.7–1.2) | 88.3% (5/6) | (36.1–97.2) | 23.7% (9/38) | (11.5–40.3) | 34% (14/44) |
aA placental pathology report was not available for 1 patient.
CI=confidence interval, IL=interleukin, intra-amniotic inflammation is defined by amniotic fluid IL-6 concentration≥2.6 ng/mL.
Acute subchorionitis/chorionitis=maternal response to acute inflammation stage 1, Acute chorioamnionitis=maternal response to acute inflammation stage 2, Necrotizing chorioamnionitis and subacute chorioamnionitis=maternal response to acute inflammation stage 3, Umbilical phlebitis/chorionic vasculitis=acute funisitis stage 1, Umbilical arteritis=acute funisitis stage 2, Necrotizing funisitis=acute funisitis stage 3.
Acute inflammatory histologic features of the placenta: acute subchorionitis, chorioamnionitis and/or acute funisitis.
Discussion
Principal findings of the study
1) The presence of acute histologic chorioamnionitis and funisitis was associated with the presence of proven intra-amniotic infection assessed by amniotic fluid analysis; 2) funisitis was also associated with the presence of FIRS; 3) the NPV of funisitis ≥stage 2 for the identification of neonates born to mothers with intra-amniotic infection was <50%, and therefore suboptimal to exclude fetal exposure to bacteria in the amniotic cavity; and 4) funisitis ≥stage 2 had an NPV of 86.8% for the identification of FIRS in a population with a prevalence of 20%. Further studies are required to determine whether molecular markers can enhance the performance of placental pathology in the identification of neonates at risk for neonatal sepsis.
Acute histologic chorioamnionitis and funisitis: two different types of inflammatory responses and their relationship with microbial invasion of the amniotic cavity
Acute histologic chorioamnionitis or chorionitis consists of the infiltration of the chorion or chorioamniotic membranes by maternal neutrophils and, therefore, is a maternal host response to chemotactic products [156, 158, 163, 170–173]. The mechanism underlying neutrophil infiltration is the presence of high concentrations of neutrophil chemokines in the amniotic fluid, which would generate a gradient promoting the migration of the neutrophils from the decidua to the chorion, and subsequently, the amnion. The following chemotactic factors have been identified in the amniotic cavity of patients in preterm labor: IL-8 [43, 48, 221–228], neutrophil activating peptide [221, 222, 229], CXCL-13 [230], leukotriene B4 [231], epithelial cell-derived neutrophil-activating peptide-78 (ENA-78) [229], Exodus-1 (CCL20) [232], and CXCL-6 [233].
Funisitis represents a fetal inflammatory response, in which circulating fetal neutrophils migrate through the umbilical vein and artery with subsequent infiltration of the Wharton’s jelly [154, 156]. The first stage of funisitis is phlebitis, followed by arteritis, and then infiltration of the Wharton’s jelly [154, 156]. Chorionic vasculitis is the equivalent of funisitis in the chorionic plate of the placenta [154].
The presence of acute chorioamnionitis diagnosed by histologic examination of the placenta has traditionally been considered as evidence of intra-amniotic infection. Indeed, this lesion is classified by the Society for Pediatric Pathology as consistent with “amniotic fluid infection” [156]. The scientific basis for this infection has been that several studies have shown a strong relationship between the presence of bacteria in the amniotic fluid and acute inflammatory lesions of the placenta in patients who delivered within 48 h of amniocentesis with preterm labor and intact membranes. For example, in a population of patients with preterm labor and intact membranes, where the prevalence of microbial invasion of the amniotic cavity (determined with cultivation techniques) was 38% (35/92), the PPV of acute funisitis was 78.7% and that of acute chorioamnionitis was 71%. The NPV for microbial invasion of the amniotic cavity, defined as a positive amniotic fluid culture, ranged between 82% for funisitis and 86% for chorioamnionitis. Similar observations have been reported by other investigators [234]. In term gestations, acute histologic chorioamnionitis is more common in patients who underwent spontaneous labor than in those who delivered by cesarean section without labor [160, 235]. Moreover, the more advanced cervical dilatation at the time of a cesarean delivery, the greater the risk of acute histologic chorioamnionitis and microbial invasion of the amniotic cavity [236, 237]. Other studies have documented that acute histologic chorioamnionitis is associated with the presence of bacteria in the chorioamniotic space [150, 151, 238], although the strength of this association varies between term and preterm gestations [172, 173]. For example, in preterm birth, the frequency of funisitis ranges from 17% to 44.8% [98, 154, 218, 239–241], while at term, funisitis is present in only 6.1%–7.2% and 1.1%–4% of cases with and without labor, respectively [157, 160, 235, 237], and its frequency is higher in patients who have rupture of the membranes [157].
Placental histologic features associated with amniotic fluid infection for the identification of neonates at risk for infection/sepsis
Acute inflammatory histologic features of the placenta are associated with microbial invasion of the amniotic cavity, intra-amniotic inflammation/infection [46, 53, 98, 147–155, 157, 159–162, 165–169, 237, 238, 242–246], and neonatal infection [147–149, 155, 245, 247–256]. A previous study reported that adding placental inflammation (amnionitis) to clinical factors (gestational age, clinical chorioamnionitis, duration of labor, maternal age, race, and parity), which are used in the identification of neonatal infection, decreased the administration of antibiotics from 35% to 10% [257]. Hoang et al. also proposed to use the presence or absence of acute histologic chorioamnionitis to guide the duration of antimicrobial treatment in neonates at risk for sepsis [258].
We report herein that the acute inflammatory histologic features of the placenta could not accurately identify neonates born to mothers with intra-amniotic infection/inflammation, or neonates with FIRS/suspected sepsis. These findings are consistent with previous reports [164, 259]. Cuna et al. reported that the presence of acute histologic chorioamnionitis did not improve the predictive performance of other biomarkers for the identification of early-onset neonatal sepsis [259]. Moreover, in that study, none of the clinically stable term infants with acute histologic chorioamnionitis had early-onset neonatal sepsis, suggesting that isolated acute subchorionitis/histologic chorioamnionitis is not associated with adverse neonatal outcomes or the requirement of antimicrobial treatment [259]. Other investigators have also reported that 38% (53/139) of patients with “clinical chorioamnionitis” did not have histologic evidence of chorioamnionitis [153], and that only 4% of women at term gestation with acute histologic chorioamnionitis were found to have microorganisms in the placenta, despite using both cultivation and molecular microbiologic techniques [164]. These observations, as well as our findings reported herein, indicate that the conventional methods to examine the human placenta with hematoxylin and eosin have limitations in determining whether intra-amniotic infection was present or whether the inflammatory response in the umbilical cord can be attributed to microorganisms.
Acute funisitis is more specific but less sensitive than acute histologic chorioamnionitis for the identification of intra-amniotic infection [154]. This is easy to understand because acute chorioamnionitis merely reflects the presence of inflammatory stimuli in the amniotic cavity, such as microorganisms or danger signals [156, 158, 163, 170–173]. However, if the microorganisms in the amniotic cavity do not invade the human fetus, funisitis should not be present.
Funisitis was reported in 70% of preterm neonates with sepsis [260]. In contrast, in our previous study, which included 832 consecutive patients who delivered within 72 h of amniocentesis, funisitis was present in 17% of patients at term with positive amniotic fluid culture for bacteria [157], and none of these neonates had neonatal sepsis. Therefore, the clinical significance of funisitis in term and preterm gestations is substantially different [157, 239]. We have proposed that microbial invasion of the amniotic cavity during the course of spontaneous labor at term is short-lived, resulting in a more modest intra-amniotic inflammatory response, as well as a lower risk of FIRS, than in preterm gestation [41]. Intra-amniotic infection in patients presenting with an episode of preterm labor is likely to have occurred days or weeks before the initiation of labor and to have eventually led to the initiation of parturition with intact or ruptured membranes [261, 262]. Evidence in support of this is that patients with positive amniotic cultures for microorganisms at the time of genetic amniocentesis in the midtrimester eventually have preterm labor or preterm prelabor rupture of the membranes, which occurs frequently after a period of weeks [261–263]. Prolonged exposure to microorganisms in preterm gestations with subclinical microbial invasion of the amniotic cavity is more likely to result in fetal invasion. This would explain why congenital neonatal sepsis is more frequent in preterm than in term neonates [264, 265]. This view is consistent with our report about the differences in fetal IL-6 umbilical cord concentrations in response to microbial invasion of the amniotic cavity between term and preterm gestations [41].
The most likely explanation for the limitations of placental pathology to identify intra-amniotic infection is that the inflammation of the chorioamniotic membranes is a non-specific mechanism of host defense against danger signals of both microbial and non-microbial origin. We have recently reported that sterile intra-amniotic inflammation is common in patients with clinical chorioamnionitis at term [1], preterm labor with intact membranes [36, 39], preterm prelabor rupture of the membranes [35], and a short cervix [37]. These patients often exhibit evidence of acute chorioamnionitis in the absence of microorganisms in the amniotic fluid. The mechanisms responsible for the acute inflammatory response in the absence of microorganisms remain to be discovered, although we have previously proposed that alarmins could also play a role [39, 54]. The possibility that patients with sterile inflammation may have had an intra-amniotic infection controlled by the host, which leads to eradication of the microorganisms but an unresolved intra-amniotic inflammatory response, cannot be excluded.
In the current study, we focused on examining the relationship between placental histology and FIRS, because it is now evident that many of the complications of infection are mediated by the effects of systemic inflammation rather than the presence of organisms [177–209]. Indeed, patients could have asymptomatic bacteremia, which is transient and does not have adverse outcomes; yet, the combination of bacteria and systemic inflammation can lead to sepsis or septic shock [26–28, 32, 133]. In addition, the presence of FIRS or neonatal systemic inflammation is associated with adverse outcomes, even in the absence of detectable bacteria by cultivation and molecular microbiologic techniques, suggesting that an exaggerated inflammatory response plays a major role in neonatal outcomes [82, 98, 177–209, 266]. Previous studies have also shown a correlation between the concentrations of TNF-α in neonatal blood and the progression of neonatal sepsis to septic shock [267, 268].
Strengths and limitations
The major strength of this study is that both cultivation and molecular microbiologic techniques were used to identify microorganisms in the amniotic cavity; therefore, the diagnosis of microbial invasion was based on state-of-the-art methodologies. However, a larger sample size and replication are desirable. The use of molecular markers to identify the presence of microorganisms in the extrachorionic membranes, chorionic plate, and umbilical cord could be an important approach in providing morphologic evidence of the location of microorganisms in different sites. This could be accomplished using fluorescent in situ hybridization with probes aimed at identifying the conserved regions of the prokaryote genome, or alternatively, using stains for bacteria in tissues [161, 269]. Similarly, markers for neutrophil activation can improve the performance of conventional examination of the placenta [270].
Conclusion
Acute histologic chorioamnionitis and funisitis are associated with intra-amniotic infection and the presence of FIRS. Current pathologic methods have limitations in the identification of the fetus exposed to microorganisms present in the amniotic cavity. The use of molecular methods to identify bacteria in tissues and neutrophil activation may improve the performance of histologic examination of the placenta in the prediction of neonates at risk for sepsis.
Acknowledgments
This research was supported, in part, by the Perinatology Research Branch, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services (NICHD/NIH); and, in part, with Federal funds from NICHD, NIH under Contract No. HSN275201300006C.
References
[1] Romero R, Miranda J, Kusanovic JP, Chaiworapongsa T, Chaemsaithong P, Martinez A, et al. Clinical chorioamnionitis at term I: microbiology of the amniotic cavity using cultivation and molecular techniques. J Perinat Med. 2015;43:19–36.10.1515/jpm-2014-0249Search in Google Scholar
[2] Gibbs RS. Diagnosis of intra-amniotic infection. Semin Perinatol. 1977;1:71–7.Search in Google Scholar
[3] Romero R, Chaemsaithong P, Korzeniewski SJ, Kusanovic JP, Docheva N, Martinez-Varea A, et al. Clinical chorioamnionitis at term III: how well do clinical criteria perform in the identification of proven intra-amniotic infection? J Perinat Med. 2016;44:23–32.10.1515/jpm-2015-0044Search in Google Scholar
[4] Gibbs RS, Castillo MS, Rodgers PJ. Management of acute chorioamnionitis. Am J Obstet Gynecol. 1980;136:709–13.10.1016/0002-9378(80)90445-7Search in Google Scholar
[5] Gibbs RS, Blanco JD, St Clair PJ, Castaneda YS. Quantitative bacteriology of amniotic fluid from women with clinical intraamniotic infection at term. J Infect Dis. 1982;145:1–8.10.1093/infdis/145.1.1Search in Google Scholar PubMed
[6] MacVicar J. Chorioamnionitis. Clin Obstet Gynecol. 1970;13:272–90.10.1097/00003081-197006000-00005Search in Google Scholar PubMed
[7] Hollander D. Diagnosis of chorioamnionitis. Clin Obstet Gynecol. 1986;29:816–25.10.1097/00003081-198612000-00008Search in Google Scholar PubMed
[8] Newton ER. Chorioamnionitis and intraamniotic infection. Clin Obstet Gynecol. 1993;36:795–808.10.1097/00003081-199312000-00004Search in Google Scholar PubMed
[9] Romero R, Chaemsaithong P, Korzeniewski SJ, Tarca AL, Bhatti G, Xu Z, et al. Clinical chorioamnionitis at term II: the intra-amniotic inflammatory response. J Perinat Med. 2016;44:5–22.Search in Google Scholar
[10] Romero R, Chaemsaithong P, Docheva N, Korzeniewski SJ, Tarca AL, Bhatti G, et al. Clinical chorioamnionitis at term IV: the maternal plasma cytokine profile. J Perinat Med. 2016;44:77–98.Search in Google Scholar
[11] Romero R, Chaemsaithoing P, Docheva N, Korzeniewski SJ, Tarca AL, Bhatti G, et al. Clinical chorioamnionitis at term V: umbilical cord plasma cytokine profile in the context of a systemic maternal inflammatory response. J Perinat Med. 2016;44:53–76.Search in Google Scholar
[12] Tita AT, Andrews WW. Diagnosis and management of clinical chorioamnionitis. Clin Perinatol. 2010;37:339–54.10.1016/j.clp.2010.02.003Search in Google Scholar PubMed PubMed Central
[13] Romero R, Chaiworapongsa T, Savasan ZA, Hussein Y, Dong Z, Kusanovic JP, et al. Clinical chorioamnionitis is characterized by changes in the expression of the alarmin HMGB1 and one of its receptors, sRAGE. J Matern Fetal Neonatal Med. 2012;25:558–67.10.3109/14767058.2011.599083Search in Google Scholar PubMed PubMed Central
[14] Fishman SG, Gelber SE. Evidence for the clinical management of chorioamnionitis. Semin Fetal & Neonatal Medicine 2012;17:46–50.10.1016/j.siny.2011.09.002Search in Google Scholar PubMed
[15] Yoder PR, Gibbs RS, Blanco JD, Castaneda YS, St Clair PJ. A prospective, controlled study of maternal and perinatal outcome after intra-amniotic infection at term. Am J Obstet Gynecol. 1983;145:695–701.10.1016/0002-9378(83)90575-6Search in Google Scholar
[16] Yancey MK, Duff P, Kubilis P, Clark P, Frentzen BH. Risk factors for neonatal sepsis. Obstet Gynecol. 1996;87:188–94.10.1016/0029-7844(95)00402-5Search in Google Scholar
[17] Ladfors L, Tessin I, Mattsson LA, Eriksson M, Seeberg S, Fall O. Risk factors for neonatal sepsis in offspring of women with prelabor rupture of the membranes at 34–42 weeks. J Perinat Med. 1998;26:94–101.10.1515/jpme.1998.26.2.94Search in Google Scholar PubMed
[18] Alexander JM, McIntire DM, Leveno KJ. Chorioamnionitis and the prognosis for term infants. Obstet Gynecol. 1999;94:274–8.Search in Google Scholar
[19] Benitz WE, Gould JB, Druzin ML. Risk factors for early-onset group B streptococcal sepsis: estimation of odds ratios by critical literature review. Pediatrics. 1999;103:e77.10.1542/peds.103.6.e77Search in Google Scholar PubMed
[20] Volante E, Moretti S, Pisani F, Bevilacqua G. Early diagnosis of bacterial infection in the neonate. J Matern Fetal Neonatal Med. 2004;16(Suppl 2):13–6.10.1080/jmf.16.2.13.16Search in Google Scholar
[21] Rouse DJ, Landon M, Leveno KJ, Leindecker S, Varner MW, Caritis SN, et al. The Maternal-Fetal Medicine Units cesarean registry: chorioamnionitis at term and its duration-relationship to outcomes. Am J Obstet Gynecol. 2004;191:211–6.10.1016/j.ajog.2004.03.003Search in Google Scholar PubMed
[22] Uyemura A, Ameel B, Caughey A. 425. Outcomes of chorioamnionitis in term pregnancies. Am J Obstet Gynecol. 2014;210:S215.10.1016/j.ajog.2013.10.458Search in Google Scholar
[23] Pappas A, Kendrick DE, Shankaran S, Stoll BJ, Bell EF, Laptook AR, et al. Chorioamnionitis and early childhood outcomes among extremely low-gestational-age neonates. J Am Med Assoc Pediatr. 2014;168:137–47.10.1001/jamapediatrics.2013.4248Search in Google Scholar PubMed PubMed Central
[24] Qazi SA, Stoll BJ. Neonatal sepsis: a major global public health challenge. Pediatr infect Dis J. 2009;28(Suppl 1):S1–2.10.1097/INF.0b013e31819587a9Search in Google Scholar PubMed
[25] Ganatra HA, Stoll BJ, Zaidi AK. International perspective on early-onset neonatal sepsis. Clin Perinatol. 2010;37:501–23.10.1016/j.clp.2010.02.004Search in Google Scholar PubMed
[26] Polin RA. Management of neonates with suspected or proven early-onset bacterial sepsis. Pediatrics. 2012;129:1006–15.10.1542/peds.2012-0541Search in Google Scholar PubMed
[27] Puopolo KM. Response to the American Academy of Pediatrics, Committee on the Fetus and Newborn statement, “management of neonates with suspected or proven early-onset bacterial sepsis”. Pediatrics. 2012;130:e1054–5; author reply e5–7.10.1542/peds.2012-2302CSearch in Google Scholar PubMed
[28] Polin R. In reply, clinical report: management of neonates with suspected or proven early-onset bacterial sepsis. Pediatrics. 2012;130:e1055–7.Search in Google Scholar
[29] Bhatti M, Chu A, Hageman JR, Schreiber M, Alexander K. Future directions in the evaluation and management of neonatal sepsis. NeoReviews. 2012;13:e103–e10.10.1542/neo.13-2-e103Search in Google Scholar
[30] Camacho-Gonzalez A, Spearman PW, Stoll BJ. Neonatal infectious diseases: evaluation of neonatal sepsis. Pediatr Clin North Am. 2013;60:367–89.10.1016/j.pcl.2012.12.003Search in Google Scholar PubMed PubMed Central
[31] Brady MT, Polin RA. Prevention and management of infants with suspected or proven neonatal sepsis. Pediatrics. 2013;132:166–8.10.1542/peds.2013-1310Search in Google Scholar PubMed
[32] Polin RA, Watterberg K, Benitz W, Eichenwald E. The conundrum of early-onset sepsis. Pediatrics. 2014;133:1122–3.10.1542/peds.2014-0360Search in Google Scholar PubMed
[33] Shane AL, Stoll BJ. Neonatal sepsis: progress towards improved outcomes. J Infection. 2014;68(Suppl 1):S24–32.10.1016/j.jinf.2013.09.011Search in Google Scholar PubMed
[34] Benitz WE, Wynn JL, Polin RA. Reappraisal of guidelines for management of neonates with suspected early-onset sepsis. J Pediatr. 2015;166:1070–4.10.1016/j.jpeds.2014.12.023Search in Google Scholar PubMed PubMed Central
[35] Romero R, Miranda J, Chaemsaithong P, Chaiworapongsa T, Kusanovic JP, Dong Z, et al. Sterile and microbial-associated intra-amniotic inflammation in preterm prelabor rupture of membranes. J Matern Fetal Neonatal Med. 2014:1–16. [Epub ahead of print].10.3109/14767058.2014.958463Search in Google Scholar PubMed PubMed Central
[36] Romero R, Miranda J, Chaiworapongsa T, Chaemsaithong P, Gotsch F, Dong Z, et al. A novel molecular microbiologic technique for the rapid diagnosis of microbial invasion of the amniotic cavity and intra-amniotic infection in preterm labor with intact membranes. Am J Reprod Immunol. 2014;71:330–58.10.1111/aji.12189Search in Google Scholar PubMed PubMed Central
[37] Romero R, Miranda J, Chaiworapongsa T, Chaemsaithong P, Gotsch F, Dong Z, et al. Sterile intra-amniotic inflammation in asymptomatic patients with a sonographic short cervix: prevalence and clinical significance. J Matern Fetal Neonatal Med. 2014:1–17. [Epub ahead of print].10.3109/14767058.2014.954243Search in Google Scholar PubMed PubMed Central
[38] Romero R, Kadar N, Miranda J, Korzeniewski SJ, Schwartz AG, Chaemsaithong P, et al. The diagnostic performance of the Mass Restricted (MR) score in the identification of microbial invasion of the amniotic cavity or intra-amniotic inflammation is not superior to amniotic fluid interleukin-6. J Matern Fetal Neonatal Med. 2014;27:757–69.10.3109/14767058.2013.844123Search in Google Scholar PubMed PubMed Central
[39] Romero R, Miranda J, Chaiworapongsa T, Korzeniewski SJ, Chaemsaithong P, Gotsch F, et al. Prevalence and clinical significance of sterile intra-amniotic inflammation in patients with preterm labor and intact membranes. Am J Reprod Immunol. 2014;72:458–74.10.1111/aji.12296Search in Google Scholar PubMed PubMed Central
[40] Yoon BH, Romero R, Kim M, Kim EC, Kim T, Park JS, et al. Clinical implications of detection of Ureaplasma urealyticum in the amniotic cavity with the polymerase chain reaction. Am J Obstet Gynecol. 2000;183:1130–7.10.1067/mob.2000.109036Search in Google Scholar PubMed
[41] Yoon BH, Romero R, Moon J, Chaiworapongsa T, Espinoza J, Kim YM, et al. Differences in the fetal interleukin-6 response to microbial invasion of the amniotic cavity between term and preterm gestation. J Matern Fetal Neonatal Med. 2003;13:32–8.10.1080/jmf.13.1.32.38Search in Google Scholar PubMed
[42] Jacobsson B, Mattsby-Baltzer I, Andersch B, Bokstrom H, Holst RM, Nikolaitchouk N, et al. Microbial invasion and cytokine response in amniotic fluid in a Swedish population of women with preterm prelabor rupture of membranes. Acta Obstet Gynecol Scand. 2003;82:423–31.10.1034/j.1600-0412.2003.00157.xSearch in Google Scholar PubMed
[43] Jacobsson B, Mattsby-Baltzer I, Andersch B, Bokstrom H, Holst RM, Wennerholm UB, et al. Microbial invasion and cytokine response in amniotic fluid in a Swedish population of women in preterm labor. Acta Obstet Gynecol Scand. 2003;82:120–8.10.1034/j.1600-0412.2003.00047.xSearch in Google Scholar PubMed
[44] Kim M, Kim G, Romero R, Shim SS, Kim EC, Yoon BH. Biovar diversity of Ureaplasma urealyticum in amniotic fluid: distribution, intrauterine inflammatory response and pregnancy outcomes. J Perinat Med. 2003;31:146–52.10.1515/JPM.2003.020Search in Google Scholar PubMed
[45] DiGiulio DB, Romero R, Amogan HP, Kusanovic JP, Bik EM, Gotsch F, et al. Microbial prevalence, diversity and abundance in amniotic fluid during preterm labor: a molecular and culture-based investigation. PloS one. 2008;3:e3056.10.1371/journal.pone.0003056Search in Google Scholar PubMed PubMed Central
[46] DiGiulio DB, Romero R, Kusanovic JP, Gomez R, Kim CJ, Seok KS, et al. Prevalence and diversity of microbes in the amniotic fluid, the fetal inflammatory response, and pregnancy outcome in women with preterm pre-labor rupture of membranes. Am J Reprod Immunol. 2010;64:38–57.10.1111/j.1600-0897.2010.00830.xSearch in Google Scholar PubMed PubMed Central
[47] DiGiulio DB, Gervasi M, Romero R, Mazaki-Tovi S, Vaisbuch E, Kusanovic JP, et al. Microbial invasion of the amniotic cavity in preeclampsia as assessed by cultivation and sequence-based methods. J Perinat Med. 2010;38:503–13.10.1515/jpm.2010.078Search in Google Scholar PubMed PubMed Central
[48] Kacerovsky M, Celec P, Vlkova B, Skogstrand K, Hougaard DM, Cobo T, et al. Amniotic fluid protein profiles of intraamniotic inflammatory response to Ureaplasma spp. and other bacteria. PloS one. 2013;8:e60399.10.1371/journal.pone.0060399Search in Google Scholar PubMed PubMed Central
[49] Cobo T, Kacerovsky M, Jacobsson B. Amniotic fluid infection, inflammation, and colonization in preterm labor with intact membranes. Am J Obstet Gynecol. 2014;211:708.10.1016/j.ajog.2014.06.060Search in Google Scholar PubMed
[50] Kacerovsky M, Musilova I, Andrys C, Hornychova H, Pliskova L, Kostal M, et al. Prelabor rupture of membranes between 34 and 37 weeks: the intraamniotic inflammatory response and neonatal outcomes. Am J Obstet Gynecol. 2014;210:325 e1–e10.10.1016/j.ajog.2013.10.882Search in Google Scholar PubMed
[51] Romero R, Dey SK, Fisher SJ. Preterm labor: one syndrome, many causes. Science. 2014;345:760–5.10.1126/science.1251816Search in Google Scholar PubMed PubMed Central
[52] Allen-Daniels MJ, Serrano MG, Pflugner LP, Fettweis JM, Prestosa MA, Koparde VN, et al. Identification of a gene in Mycoplasma hominis associated with preterm birth and microbial burden in intraamniotic infection. Am J Obstet Gynecol. 2015. [Epub ahead of print].10.1016/j.ajog.2015.01.032Search in Google Scholar PubMed PubMed Central
[53] Yoon BH, Romero R, Moon JB, Shim SS, Kim M, Kim G, et al. Clinical significance of intra-amniotic inflammation in patients with preterm labor and intact membranes. Am J Obstet Gynecol. 2001;185:1130–6.10.1067/mob.2001.117680Search in Google Scholar PubMed
[54] Romero R, Chaiworapongsa T, Alpay Savasan Z, Xu Y, Hussein Y, Dong Z, et al. Damage-associated molecular patterns (DAMPs) in preterm labor with intact membranes and preterm PROM: a study of the alarmin HMGB1. J Matern Fetal Neonatal Med. 2011;24:1444–55.10.3109/14767058.2011.591460Search in Google Scholar PubMed PubMed Central
[55] Cobo T, Palacio M, Martinez-Terron M, Navarro-Sastre A, Bosch J, Filella X, et al. Clinical and inflammatory markers in amniotic fluid as predictors of adverse outcomes in preterm premature rupture of membranes. Am J Obstet Gynecol. 2011;205:126 e1–8.10.1016/j.ajog.2011.03.050Search in Google Scholar PubMed
[56] Chaemsaithong P, Romero R, Korzeniewski SJ, Dong Z, Yeo L, Hassan SS, et al. A point of care test for the determination of amniotic fluid interleukin-6 and the chemokine CXCL-10/IP-10. J Matern Fetal Neonatal Med. 2014:1–10.10.3109/14767058.2014.961417Search in Google Scholar PubMed PubMed Central
[57] Combs CA, Gravett M, Garite TJ, Hickok DE, Lapidus J, Porreco R, et al. Amniotic fluid infection, inflammation, and colonization in preterm labor with intact membranes. Am J Obstet Gynecol. 2014;210:125. e1–15.10.1016/j.ajog.2013.11.032Search in Google Scholar
[58] Chaemsaithong P, Romero R, Korzeniewski SJ, Dong Z, Martinez-Varea A, Yoon BH, et al. A Rapid interleukin-6 bedside test for the identification of intra-amniotic inflammation in preterm labor with intact membranes. J Matern Fetal Neonatal Med. 2015;23:1–11. [Epub ahead of print].10.3109/14767058.2015.1006620Search in Google Scholar
[59] Chaemsaithong P, Romero R, Korzeniewski SJ, Dong Z, Martinez-Varea A, Yoon BH, et al. A point of care test for interleukin-6 in amniotic fluid in preterm prelabor rupture of membrances: a step toward the early treatment of acute intra-amniotic inflammation/infection. J Matern Fetal Neonatal Med. 2015;23:1–8. [Epub ahead of print].10.3109/14767058.2015.1006621Search in Google Scholar
[60] Verani JR, McGee L, Schrag SJ, Division of Bacterial Diseases NCfI, Respiratory Diseases CfDC, Prevention. Prevention of perinatal group B streptococcal disease-revised guidelines from CDC, 2010. MMWR Recommendations and reports : Morbidity and mortality weekly report Recommendations and reports / Centers for Disease Control. 2010;59(RR-10):1–6.Search in Google Scholar
[61] Tollner U, Pohlandt F, Kleinhauer E. Neonatal infection and white blood cell count. Pediatrics. 1980;65:1196–7.10.1542/peds.65.6.1196Search in Google Scholar
[62] Philip AG. White blood cells and acute phase reactants in neonatal sepsis. Pediatrie. 1984;39:371–8.Search in Google Scholar
[63] Weinberg AG, Rosenfeld CR, Manroe BL, Browne R. Neonatal blood cell count in health and disease. II. Values for lymphocytes, monocytes, and eosinophils. J Pediatr. 1985;106:462–6.10.1016/S0022-3476(85)80681-8Search in Google Scholar
[64] Rozycki HJ, Stahl GE, Baumgart S. Impaired sensitivity of a single early leukocyte count in screening for neonatal sepsis. Pediatr Infect Dis J. 1987;6:440–2.10.1097/00006454-198705000-00004Search in Google Scholar
[65] Kumar A. Leukocyte studies in diagnosis of neonatal sepsis. J Pediatr. 1989;114:505–6.10.1016/S0022-3476(89)80585-2Search in Google Scholar
[66] Greenberg DN, Yoder BA. Changes in the differential white blood cell count in screening for group B streptococcal sepsis. Pediatr Infect Dis J. 1990;9:886–9.10.1097/00006454-199012000-00006Search in Google Scholar PubMed
[67] DaSilva O, Hammerberg O. Diagnostic value of leukocyte indices in late neonatal sepsis. Pediatr Infect Dis J. 1994;13:409–11.10.1097/00006454-199405000-00014Search in Google Scholar
[68] Berger C, Uehlinger J, Ghelfi D, Blau N, Fanconi S. Comparison of C-reactive protein and white blood cell count with differential in neonates at risk for septicaemia. Eur J Pediatr. 1995;154:138–44. .10.1007/BF01991918Search in Google Scholar PubMed
[69] Buck C, Pohlandt F. Accuracy of leukocyte indices and C-reactive protein for diagnosis of neonatal infection. Pediatr Infect Dis Journal. 1995;14:1119–20. .10.1097/00006454-199512000-00026Search in Google Scholar PubMed
[70] Da Silva O, Ohlsson A, Kenyon C. Accuracy of leukocyte indices and C-reactive protein for diagnosis of neonatal sepsis: a critical review. Pediatr Infect Dis Journal. 1995;14:362–6.10.1097/00006454-199505000-00005Search in Google Scholar PubMed
[71] Polinski C. The value of the white blood cell count and differential in the prediction of neonatal sepsis. Neonatal Network. 1996;15:13–23.Search in Google Scholar
[72] da Silva O, Ohlsson A. How accurate are leukocyte indices and C-reactive protein for diagnosis of neonatal sepsis? Paediatr Child Health. 1998;3:158–9.10.1093/pch/3.3.158Search in Google Scholar PubMed PubMed Central
[73] Faix RG. Utility of complete blood count and blood culture screening to diagnose neonatal sepsis in the asymptomatic at-risk newborn. J Pediatr. 2003;143:686–7.Search in Google Scholar
[74] Ottolini MC, Lundgren K, Mirkinson LJ, Cason S, Ottolini MG. Utility of complete blood count and blood culture screening to diagnose neonatal sepsis in the asymptomatic at risk newborn. Pediatr Infect Dis J. 2003;22:430–4.10.1097/01.inf.0000068206.11303.ddSearch in Google Scholar PubMed
[75] Hornik CP, Benjamin DK, Becker KC, Benjamin DK, Jr., Li J, Clark RH, et al. Use of the complete blood cell count in late-onset neonatal sepsis. Pediatr Infect Dis J. 2012;31:803–7.10.1097/INF.0b013e31825691e4Search in Google Scholar PubMed PubMed Central
[76] Resch B, Edlinger S, Muller W. White blood cell counts in neonatal early-onset sepsis. Pediatr Infect Dis J. 2012;31:540-1; author reply 1.10.1097/INF.0b013e31824e4740Search in Google Scholar PubMed
[77] Murphy K, Weiner J. Use of leukocyte counts in evaluation of early-onset neonatal sepsis. Pediatr Infect Dis J. 2012;31:16–9.10.1097/INF.0b013e31822ffc17Search in Google Scholar PubMed
[78] Mussap M. Laboratory medicine in neonatal sepsis and inflammation. J Matern Fetal Neonatal Med. 2012;25(Suppl 4): 32–4.10.3109/14767058.2012.715000Search in Google Scholar PubMed
[79] Hornik CP, Benjamin DK, Becker KC, Benjamin DK, Jr., Li J, Clark RH, et al. Use of the complete blood cell count in early-onset neonatal sepsis. Pediatr Infect Dis J. 2012;31:799–802.10.1097/INF.0b013e318256905cSearch in Google Scholar PubMed PubMed Central
[80] Makkar M, Gupta C, Pathak R, Garg S, Mahajan NC. Performance evaluation of hematologic scoring system in early diagnosis of neonatal sepsis. J Clin Neonat. 2013;2:25–9.10.4103/2249-4847.109243Search in Google Scholar PubMed PubMed Central
[81] Ng PC. Diagnostic markers of infection in neonates. Arch Dis Child Fetal Neonatal. 2004;89:F229–35.10.1136/adc.2002.023838Search in Google Scholar
[82] Shah BA, Padbury JF. Neonatal sepsis: an old problem with new insights. Virulence. 2014;5:170–8.10.4161/viru.26906Search in Google Scholar
[83] Soni S, Wadhwa N, Kumar R, Faridi MM. Use of immature-to-total-neutrophil ratio in early neonatal sepsis. Pediatr Infect Dis J. 2012;31:1101–2; author reply 2.10.1097/INF.0b013e31826108daSearch in Google Scholar
[84] Miller LC, Isa S, LoPreste G, Schaller JG, Dinarello CA. Neonatal interleukin-1 beta, interleukin-6, and tumor necrosis factor: cord blood levels and cellular production. J Pediatr. 1990;117:961–5.10.1016/S0022-3476(05)80145-3Search in Google Scholar
[85] Buck C, Bundschu J, Gallati H, Bartmann P, Pohlandt F. Interleukin-6: a sensitive parameter for the early diagnosis of neonatal bacterial infection. Pediatrics. 1994;93:54–8.10.1542/peds.93.1.54Search in Google Scholar
[86] Lehrnbecher T, Schrod L, Kraus D, Roos T, Martius J, von Stockhausen HB. Interleukin-6 and soluble interleukin-6 receptor in cord blood in the diagnosis of early onset sepsis in neonates. Acta Paediatrica. 1995;84:806–8.10.1111/j.1651-2227.1995.tb13761.xSearch in Google Scholar
[87] Lehrnbecher T, Schrod L, Rutsch P, Roos T, Martius J, von Stockhausen HB. Immunologic parameters in cord blood indicating early-onset sepsis. Biol Neonate. 1996;70:206–12.10.1159/000244366Search in Google Scholar
[88] Messer J, Eyer D, Donato L, Gallati H, Matis J, Simeoni U. Evaluation of interleukin-6 and soluble receptors of tumor necrosis factor for early diagnosis of neonatal infection. J Pediatr. 1996;129:574–80.10.1016/S0022-3476(96)70123-3Search in Google Scholar
[89] Singh B, Merchant P, Walker CR, Kryworuchko M, Diaz-Mitoma F. Interleukin-6 expression in cord blood of patients with clinical chorioamnionitis. Pediat Res. 1996;39:976–9.10.1203/00006450-199606000-00008Search in Google Scholar PubMed
[90] Smulian JC, Bhandari V, Campbell WA, Rodis JF, Vintzileos AM. Value of umbilical artery and vein levels of interleukin-6 and soluble intracellular adhesion molecule-1 as predictors of neonatal hematologic indices and suspected early sepsis. J Maternal Fetal Med. 1997;6:254–9.Search in Google Scholar
[91] Berner R, Niemeyer CM, Leititis JU, Funke A, Schwab C, Rau U, et al. Plasma levels and gene expression of granulocyte colony-stimulating factor, tumor necrosis factor-alpha, interleukin (IL)-1beta, IL-6, IL-8, and soluble intercellular adhesion molecule-1 in neonatal early onset sepsis. Pediatr Res. 1998;44:469–77.10.1203/00006450-199810000-00002Search in Google Scholar PubMed
[92] Weimann E, Rutkowski S, Reisbach G. G-CSF, GM-CSF and IL-6 levels in cord blood: diminished increase of G-CSF and IL-6 in preterms with perinatal infection compared to term neonates. J Perinat Med. 1998;26:211–8.10.1515/jpme.1998.26.3.211Search in Google Scholar PubMed
[93] Perenyi A, Johann-Liang R, Stavola JJ. Assessment of cord blood IL-6 levels as an indicator of neonatal sepsis. Am J Perinat. 1999;16:525–30.10.1055/s-1999-7282Search in Google Scholar PubMed
[94] Smulian JC, Vintzileos AM, Lai YL, Santiago J, Shen-Schwarz S, Campbell WA. Maternal chorioamnionitis and umbilical vein interleukin-6 levels for identifying early neonatal sepsis. J matern Fetal Med. 1999;8:88–94.Search in Google Scholar
[95] Silveira RC, Procianoy RS. Evaluation of interleukin-6, tumour necrosis factor-alpha and interleukin-1beta for early diagnosis of neonatal sepsis. Acta Paediatrica. 1999;88:647–50.10.1080/08035259950169314Search in Google Scholar PubMed
[96] Kashlan F, Smulian J, Shen-Schwarz S, Anwar M, Hiatt M, Hegyi T. Umbilical vein interleukin 6 and tumor necrosis factor alpha plasma concentrations in the very preterm infant. The Pediatr Infect Dis J. 2000;19:238–43.10.1097/00006454-200003000-00013Search in Google Scholar PubMed
[97] Mehr S, Doyle LW. Cytokines as markers of bacterial sepsis in newborn infants: a review. The Pediatr Infect Dis J. 2000;19:879–87.10.1097/00006454-200009000-00014Search in Google Scholar PubMed
[98] Yoon BH, Romero R, Park JS, Kim M, Oh SY, Kim CJ, et al. The relationship among inflammatory lesions of the umbilical cord (funisitis), umbilical cord plasma interleukin 6 concentration, amniotic fluid infection, and neonatal sepsis. Am J Obstet Gynecol. 2000;183:1124–9.10.1067/mob.2000.109035Search in Google Scholar PubMed
[99] Dollner H, Vatten L, Linnebo I, Zanussi GF, Laerdal A, Austgulen R. Inflammatory mediators in umbilical plasma from neonates who develop early-onset sepsis. Biol Neonate. 2001;80:41–7.10.1159/000047118Search in Google Scholar PubMed
[100] Krueger M, Nauck MS, Sang S, Hentschel R, Wieland H, Berner R. Cord blood levels of interleukin-6 and interleukin-8 for the immediate diagnosis of early-onset infection in premature infants. Biol Neonate. 2001;80:118–23.10.1159/000047130Search in Google Scholar PubMed
[101] Santana C, Guindeo MC, Gonzalez G, Garcia-Munoz F, Saavedra P, Domenech E. Cord blood levels of cytokines as predictors of early neonatal sepsis. Acta Paediatrica. 2001;90:1176–81.10.1111/j.1651-2227.2001.tb03250.xSearch in Google Scholar
[102] Dollner H, Vatten L, Halgunset J, Rahimipoor S, Austgulen R. Histologic chorioamnionitis and umbilical serum levels of pro-inflammatory cytokines and cytokine inhibitors. BJOG Int J Obstet Gynaec. 2002;109:534–9.10.1111/j.1471-0528.2002.01028.xSearch in Google Scholar
[103] Laborada G, Rego M, Jain A, Guliano M, Stavola J, Ballabh P, et al. Diagnostic value of cytokines and C-reactive protein in the first 24 hours of neonatal sepsis. Am Journal Perinat. 2003;20:491–501.10.1055/s-2003-45382Search in Google Scholar PubMed
[104] Santana Reyes C, Garcia-Munoz F, Reyes D, Gonzalez G, Dominguez C, Domenech E. Role of cytokines (interleukin-1beta, 6, 8, tumour necrosis factor-alpha, and soluble receptor of interleukin-2) and C-reactive protein in the diagnosis of neonatal sepsis. Acta Paediatrica. 2003;92:221–7.10.1111/j.1651-2227.2003.tb00530.xSearch in Google Scholar PubMed
[105] Hatzidaki E, Gourgiotis D, Manoura A, Korakaki E, Bossios A, Galanakis E, et al. Interleukin-6 in preterm premature rupture of membranes as an indicator of neonatal outcome. Acta Obstet Gynecol Scand. 2005;84:632–8.10.1111/j.0001-6349.2005.00747.xSearch in Google Scholar PubMed
[106] Ng PC, Lam HS. Diagnostic markers for neonatal sepsis. Curr Opin Pediatr. 2006;18:125–31.10.1097/01.mop.0000193293.87022.4cSearch in Google Scholar PubMed
[107] Tasci Y, Dilbaz B, Uzmez Onal B, Caliskan E, Dilbaz S, Doganci L, et al. The value of cord blood interleukin-6 levels for predicting chorioamnionitis, funisitis and neonatal infection in term premature rupture of membranes. Eur J Obstet Gynecol Reprod Biol. 2006;128:34–9.10.1016/j.ejogrb.2005.11.049Search in Google Scholar PubMed
[108] Arnon S, Litmanovitz I. Diagnostic tests in neonatal sepsis. Curr Opin Infect Dis. 2008;21:223–7.10.1097/QCO.0b013e3282fa15ddSearch in Google Scholar PubMed
[109] Veleminsky M, Jr., Stransky P, Veleminsky M, Sr., Tosner J. Relationship of IL-6, IL-8, TNF and sICAM-1 levels to PROM, pPROM, and the risk of early-onset neonatal sepsis. Neuroendocrinol Lett. 2008;29:303–11.Search in Google Scholar
[110] Prinsen JH, Baranski E, Posch H, Tober K, Gerstmeyer A. Interleukin-6 as diagnostic marker for neonatal sepsis: determination of Access IL-6 cutoff for newborns. Clin Lab. 2008;54:179–83.Search in Google Scholar
[111] Cancelier AC, Petronilho F, Reinke A, Constantino L, Machado R, Ritter C, et al. Inflammatory and oxidative parameters in cord blood as diagnostic of early-onset neonatal sepsis: a case-control study. Pediatric Critical Care Medicine : A Journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies. 2009;10:467–71.10.1097/PCC.0b013e318198b0e3Search in Google Scholar PubMed
[112] Cernada M, Badia N, Modesto V, Alonso R, Mejias A, Golombek S, et al. Cord blood interleukin-6 as a predictor of early-onset neonatal sepsis. Acta Paediatrica. 2012;101:e203-7.10.1111/j.1651-2227.2011.02577.xSearch in Google Scholar PubMed
[113] Fan Y, Yu JL. Umbilical blood biomarkers for predicting early-onset neonatal sepsis. World J Pediatr. 2012;8:101–8.10.1007/s12519-012-0347-3Search in Google Scholar PubMed
[114] Hassanein SM, El-Farrash RA, Hafez HM, Hassanin OM, Abd El Rahman NA. Cord blood interleukin-6 and neonatal morbidities among preterm infants with PCR-positive Ureaplasma urealyticum. J Matern Fetal Neonatal Med. 2012;25:2106–10.10.3109/14767058.2012.678435Search in Google Scholar PubMed
[115] Cobo T, Kacerovsky M, Andrys C, Drahosova M, Musilova I, Hornychova H, et al. Umbilical cord blood IL-6 as predictor of early-onset neonatal sepsis in women with preterm prelabour rupture of membranes. PloS one. 2013;8:e69341.10.1371/journal.pone.0069341Search in Google Scholar PubMed PubMed Central
[116] Prashant A, Vishwanath P, Kulkarni P, Sathya Narayana P, Gowdara V, Nataraj SM, et al. Comparative assessment of cytokines and other inflammatory markers for the early diagnosis of neonatal sepsis-a case control study. PloS one. 2013;8:e68426.10.1371/journal.pone.0068426Search in Google Scholar PubMed PubMed Central
[117] Sorokin Y, Romero R, Mele L, Iams JD, Peaceman AM, Leveno KJ, et al. Umbilical cord serum interleukin-6, C-reactive protein, and myeloperoxidase concentrations at birth and association with neonatal morbidities and long-term neurodevelopmental outcomes. Am J Perinat. 2014;31:717–26.Search in Google Scholar
[118] Su H, Chang SS, Han CM, Wu KY, Li MC, Huang CY, et al. Inflammatory markers in cord blood or maternal serum for early detection of neonatal sepsis-a systemic review and meta-analysis. J Perinat: Official J California Perinatal Association. 2014;34:268–74.10.1038/jp.2013.186Search in Google Scholar PubMed
[119] Berner R, Tuxen B, Clad A, Forster J, Brandis M. Elevated gene expression of interleukin-8 in cord blood is a sensitive marker for neonatal infection. Eur J Pediat. 2000;159:205–10.10.1007/s004310050051Search in Google Scholar PubMed
[120] Sabel KG, Wadsworth C. C-reactive protein (CRP) in early diagnosis of neonatal septicemia. Acta Paediatrica Scand. 1979;68:825–31.Search in Google Scholar
[121] Hindocha P, Campbell CA, Gould JD, Wojciechowski A, Wood CB. Serial study of C reactive protein in neonatal septicaemia. Arch Dis Child. 1984;59:435–8.10.1136/adc.59.5.435Search in Google Scholar PubMed PubMed Central
[122] Mishra UK, Jacobs SE, Doyle LW, Garland SM. Newer approaches to the diagnosis of early onset neonatal sepsis. Arch Dis Child Fetal Neonat. 2006;91:F208–12.10.1136/adc.2004.064188Search in Google Scholar PubMed PubMed Central
[123] Joram N, Boscher C, Denizot S, Loubersac V, Winer N, Roze JC, et al. Umbilical cord blood procalcitonin and C reactive protein concentrations as markers for early diagnosis of very early onset neonatal infection. Arch Dis Child Fetal Neonat. 2006;91:F65–6.10.1136/adc.2005.074245Search in Google Scholar PubMed PubMed Central
[124] Kordek A, Halasa M, Podraza W. Early detection of an early onset infection in the neonate based on measurements of procalcitonin and C-reactive protein concentrations in cord blood. Clin Chem Lab Med. 2008;46:1143–8.10.1515/CCLM.2008.214Search in Google Scholar PubMed
[125] Howman RA, Charles AK, Jacques A, Doherty DA, Simmer K, Strunk T, et al. Inflammatory and haematological markers in the maternal, umbilical cord and infant circulation in histological chorioamnionitis. PloS one. 2012;7:e51836.10.1371/journal.pone.0051836Search in Google Scholar PubMed PubMed Central
[126] Janota J, Stranak Z, Belohlavkova S, Mudra K, Simak J. Postnatal increase of procalcitonin in premature newborns is enhanced by chorioamnionitis and neonatal sepsis. Eur J Clin Invest. 2001;31:978–83.10.1046/j.1365-2362.2001.00912.xSearch in Google Scholar PubMed
[127] Kordek A, Giedrys-Kalemba S, Pawlus B, Podraza W, Czajka R. Umbilical cord blood serum procalcitonin concentration in the diagnosis of early neonatal infection. J Perinat: Official J California Perinatal Association. 2003;23:148–53.10.1038/sj.jp.7210885Search in Google Scholar
[128] Llorente E, Prieto B, Cardo L, Avello N, Alvarez FV. Umbilical cord blood serum procalcitonin by Time-Resolved Amplified Cryptate Emission (TRACE) technology: reference values of a potential marker of vertically transmitted neonatal sepsis. Clin Chem Lab Med. 2007;45:1531–5.10.1515/CCLM.2007.304Search in Google Scholar
[129] Dietzman DE, Fischer GW, Schoenknecht FD. Neonatal Escherichia coli septicemia-bacterial counts in blood. J Pediat. 1974;85:128–30.10.1016/S0022-3476(74)80308-2Search in Google Scholar
[130] Polin JI, Knox I, Baumgart S, Campman E, Mennuti MT, Polin RA. Use of umbilical cord blood culture for detection of neonatal bacteremia. Obstet Gynecol. 1981;57:233–7.Search in Google Scholar
[131] Neal PR, Kleiman MB, Reynolds JK, Allen SD, Lemons JA, Yu PL. Volume of blood submitted for culture from neonates. J Clin Microbiol. 1986;24:353–6.10.1128/jcm.24.3.353-356.1986Search in Google Scholar
[132] Kellogg JA, Ferrentino FL, Goodstein MH, Liss J, Shapiro SL, Bankert DA. Frequency of low level bacteremia in infants from birth to two months of age. Pediat Infect Dis J. 1997;16: 381–5.10.1097/00006454-199704000-00009Search in Google Scholar
[133] Polin RA. The “ins and outs” of neonatal sepsis. J Pediatr. 2003;143:3–4.10.1016/S0022-3476(03)00271-3Search in Google Scholar
[134] Connell TG, Rele M, Cowley D, Buttery JP, Curtis N. How reliable is a negative blood culture result? Volume of blood submitted for culture in routine practice in a children’s hospital. Pediatrics. 2007;119:891–6.10.1542/peds.2006-0440Search in Google Scholar PubMed
[135] Hendricks-Munoz KD, Shapiro DL. The role of the lumbar puncture in the admission sepsis evaluation of the premature infant. J Perinat: Official J California Perinatal Association. 1990;10:60–4.Search in Google Scholar
[136] Wiswell TE, Baumgart S, Gannon CM, Spitzer AR. No lumbar puncture in the evaluation for early neonatal sepsis: will meningitis be missed? Pediatrics. 1995;95:803–6.Search in Google Scholar
[137] Kumar P, Sarkar S, Narang A. Role of routine lumbar puncture in neonatal sepsis. J Paediatr Child H. 1995;31:8–10.10.1111/j.1440-1754.1995.tb02902.xSearch in Google Scholar PubMed
[138] McIntyre P, Isaacs D. Lumbar puncture in suspected neonatal sepsis. J Paediatr Child H. 1995;31:1–2.10.1111/j.1440-1754.1995.tb02899.xSearch in Google Scholar PubMed
[139] Beeram M, Oltorf C, Cipriani C. Lumbar puncture in the evaluation for early neonatal sepsis. Pediatrics. 1996;97(6 Pt 1):930; author reply -1.10.1542/peds.97.6.930Search in Google Scholar
[140] Tierney AJ, Finer NN. Lumbar puncture in the evaluation for early neonatal sepsis. Pediatrics. 1996;97(6 Pt 1):929–30.10.1542/peds.97.6.929bSearch in Google Scholar
[141] Stoll BJ, Hansen N, Fanaroff AA, Wright LL, Carlo WA, Ehrenkranz RA, et al. To tap or not to tap: high likelihood of meningitis without sepsis among very low birth weight infants. Pediatrics. 2004;113:1181–6.10.1542/peds.113.5.1181Search in Google Scholar
[142] Ray B, Mangalore J, Harikumar C, Tuladhar A. Is lumbar puncture necessary for evaluation of early neonatal sepsis? Arch Dis Child. 2006;91:1033–5.10.1136/adc.2006.105106Search in Google Scholar
[143] Garges HP, Moody MA, Cotten CM, Smith PB, Tiffany KF, Lenfestey R, et al. Neonatal meningitis: what is the correlation among cerebrospinal fluid cultures, blood cultures, and cerebrospinal fluid parameters? Pediatrics. 2006;117:1094–100.10.1542/peds.2005-1132Search in Google Scholar
[144] Mhanna MJ, Alesseh H, Gori A, Aziz HF. Cerebrospinal fluid values in very low birth weight infants with suspected sepsis at different ages. Pediatric Critical Care Medicine: A Journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies. 2008;9:294–8.10.1097/01.PCC.0b013e31816c6e12Search in Google Scholar
[145] Kiser C, Nawab U, McKenna K, Aghai ZH. Role of guidelines on length of therapy in chorioamnionitis and neonatal sepsis. Pediatrics. 2014;133:992–8.10.1542/peds.2013-2927Search in Google Scholar
[146] Benirschke K, Clifford SH. Intrauterine bacterial infection of the newborn infant: frozen sections of the cord as an aid to early detection. J Pediatr. 1959;54:11–8.10.1016/S0022-3476(59)80031-7Search in Google Scholar
[147] Olding L. Value of placentitis as a sign of intrauterine infection in human subjects. Acta Pathol Microbiol Scand A. 1970;78:256–64.10.1111/j.1699-0463.1970.tb03300.xSearch in Google Scholar PubMed
[148] Zhang JM, Kraus FT, Aquino TI. Chorioamnionitis: a comparative histologic, bacteriologic, and clinical study. Int J Gynecol Pathol. 1985;4:1–10.10.1097/00004347-198501000-00001Search in Google Scholar
[149] Svensson L, Ingemarsson I, Mardh PA. Chorioamnionitis and the isolation of microorganisms from the placenta. Obstet Gynecol. 1986;67:403–9.Search in Google Scholar
[150] Hillier SL, Martius J, Krohn M, Kiviat N, Holmes KK, Eschenbach DA. A case-control study of chorioamnionic infection and histologic chorioamnionitis in prematurity. N Engl J Med. 1988;319:972–8.10.1056/NEJM198810133191503Search in Google Scholar PubMed
[151] Hillier SL, Krohn MA, Kiviat NB, Watts DH, Eschenbach DA. Microbiologic causes and neonatal outcomes associated with chorioamnion infection. Am J Obstet Gynecol. 1991;165(4 Pt 1):955–61.10.1016/0002-9378(91)90447-YSearch in Google Scholar
[152] van Hoeven KH, Anyaegbunam A, Hochster H, Whitty JE, Distant J, Crawford C, et al. Clinical significance of increasing histologic severity of acute inflammation in the fetal membranes and umbilical cord. Pediatr Pathol Lab Med. 1996;16:731–44.10.3109/15513819609169300Search in Google Scholar
[153] Smulian JC, Shen-Schwarz S, Vintzileos AM, Lake MF, Ananth CV. Clinical chorioamnionitis and histologic placental inflammation. Obstet Gynecol. 1999;94:1000–5.Search in Google Scholar
[154] Pacora P, Chaiworapongsa T, Maymon E, Kim YM, Gomez R, Yoon BH, et al. Funisitis and chorionic vasculitis: the histological counterpart of the fetal inflammatory response syndrome. J Matern Fetal Neonatal Med. 2002;11:18–25.10.1080/jmf.11.1.18.25Search in Google Scholar
[155] Rhone SA, Magee F, Remple V, Money D. The association of placental abnormalities with maternal and neonatal clinical findings: a retrospective cohort study. J Obstet Gynaecol Can. 2003;25:123–8.10.1016/S1701-2163(16)30208-0Search in Google Scholar
[156] Redline RW, Heller D, Keating S, Kingdom J. Placental diagnostic criteria and clinical correlation-a workshop report. Placenta. 2005;26(Suppl A):S114–7.10.1016/j.placenta.2005.02.009Search in Google Scholar PubMed
[157] Lee SE, Romero R, Kim CJ, Shim SS, Yoon BH. Funisitis in term pregnancy is associated with microbial invasion of the amniotic cavity and intra-amniotic inflammation. J Matern Fetal Neonatal Med. 2006;19:693–7.10.1080/14767050600927353Search in Google Scholar PubMed
[158] Redline RW. Inflammatory responses in the placenta and umbilical cord. Semin Fetal Neonatal Med. 2006;11:296–301.10.1016/j.siny.2006.02.011Search in Google Scholar PubMed
[159] Lee SE, Romero R, Jung H, Park CW, Park JS, Yoon BH. The intensity of the fetal inflammatory response in intraamniotic inflammation with and without microbial invasion of the amniotic cavity. Am J Obstet Gynecol. 2007;197:294 e1–6.10.1016/j.ajog.2007.07.006Search in Google Scholar PubMed
[160] Seong HS, Lee SE, Kang JH, Romero R, Yoon BH. The frequency of microbial invasion of the amniotic cavity and histologic chorioamnionitis in women at term with intact membranes in the presence or absence of labor. Am J Obstet Gynecol. 2008;199:375 e1–5.10.1016/j.ajog.2008.06.040Search in Google Scholar PubMed PubMed Central
[161] Kim MJ, Romero R, Gervasi MT, Kim JS, Yoo W, Lee DC, et al. Widespread microbial invasion of the chorioamniotic membranes is a consequence and not a cause of intra-amniotic infection. Lab Invest. 2009;89:924–36.10.1038/labinvest.2009.49Search in Google Scholar PubMed PubMed Central
[162] Park CW, Moon KC, Park JS, Jun JK, Romero R, Yoon BH. The involvement of human amnion in histologic chorioamnionitis is an indicator that a fetal and an intra-amniotic inflammatory response is more likely and severe: clinical implications. Placenta. 2009;30:56–61.10.1016/j.placenta.2008.09.017Search in Google Scholar PubMed PubMed Central
[163] Redline RW. Inflammatory response in acute chorioamnionitis. Semin Fetal Neonatal Med. 2012;17:20–5.10.1016/j.siny.2011.08.003Search in Google Scholar PubMed
[164] Roberts DJ, Celi AC, Riley LE, Onderdonk AB, Boyd TK, Johnson LC, et al. Acute histologic chorioamnionitis at term: nearly always noninfectious. PloS one. 2012;7:e31819.10.1371/journal.pone.0031819Search in Google Scholar PubMed PubMed Central
[165] Lee SM, Park JW, Kim BJ, Park CW, Park JS, Jun JK, et al. Acute histologic chorioamnionitis is a risk factor for adverse neonatal outcome in late preterm birth after preterm premature rupture of membranes. PloS one. 2013;8:e79941.10.1371/journal.pone.0079941Search in Google Scholar PubMed PubMed Central
[166] Park CW, Yoon BH, Kim SM, Park JS, Jun JK. Which is more important for the intensity of intra-amniotic inflammation between total grade or involved anatomical region in preterm gestations with acute histologic chorioamnionitis? Obstet Gynecol Sci. 2013;56:227–33.10.5468/ogs.2013.56.4.227Search in Google Scholar PubMed PubMed Central
[167] Park CW, Yoon BH, Park JS, Jun JK. A fetal and an intra-amniotic inflammatory response is more severe in preterm labor than in preterm PROM in the context of funisitis: unexpected observation in human gestations. PloS one. 2013;8:e62521.10.1371/journal.pone.0062521Search in Google Scholar PubMed PubMed Central
[168] Kim SM, Romero R, Park JW, Oh KJ, Jun JK, Yoon BH. The relationship between the intensity of intra-amniotic inflammation and the presence and severity of acute histologic chorioamnionitis in preterm gestation. J Matern Fetal Neonatal Med. 2014:1–10. [Epub ahead of print].10.3109/14767058.2014.961009Search in Google Scholar PubMed PubMed Central
[169] Park CW, Kim SM, Park JS, Jun JK, Yoon BH. Fetal, amniotic and maternal inflammatory responses in early stage of ascending intrauterine infection, inflammation restricted to chorio-decidua, in preterm gestation. J Matern Fetal Neonatal Med. 2014;27:98–105.10.3109/14767058.2013.806898Search in Google Scholar PubMed
[170] Murtha AP, Auten R, Herbert WN. Apoptosis in the chorion laeve of term patients with histologic chorioamnionitis. Infect Dis Obstet Gynecol. 2002;10:93–6.10.1155/S106474490200008XSearch in Google Scholar PubMed PubMed Central
[171] George RB, Kalich J, Yonish B, Murtha AP. Apoptosis in the chorion of fetal membranes in preterm premature rupture of membranes. Am J Perinat. 2008;25:29–32.10.1055/s-2007-1004828Search in Google Scholar PubMed
[172] Menon R, Taylor RN, Fortunato SJ. Chorioamnionitis-a complex pathophysiologic syndrome. Placenta. 2010;31:113–20.10.1016/j.placenta.2009.11.012Search in Google Scholar
[173] Conti N, Torricelli M, Voltolini C, Vannuccini S, Clifton VL, Bloise E, et al. Term histologic chorioamnionitis: a heterogeneous condition. Eur J Obstet Gynecol Reprod Biol. 2015;188:34–8.10.1016/j.ejogrb.2015.02.034Search in Google Scholar
[174] Mendilcioglu I, Kilicarslan B, Gurkan Zorlu C, Karaveli S, Uner M, Trak B. Placental biopsy by frozen section: does it have a role in evaluation of fetal well-being? Aust NZ J Obstet Gynaecol. 2003;43:433–7.10.1046/j.0004-8666.2003.00128.xSearch in Google Scholar
[175] Beaudet L, Karuri S, Lau J, Magee F, Lee SK, von Dadelszen P. Placental pathology and clinical outcomes in a cohort of infants admitted to a neonatal intensive care unit. J Obstet Gynaecol Can. 2007;29:315–23.10.1016/S1701-2163(16)32431-8Search in Google Scholar
[176] Mahe E, Hamid J, Terry J, Jansen JW, Bourgeois J, Arredondo-Marin J. Frozen section of placental membranes and umbilical cord: an aid to early postpartum diagnosis of intra-amniotic infection. Am J Clin Pathol. 2014;142:202–8.10.1309/AJCPYN70DLUFFDVPSearch in Google Scholar
[177] Romero R, Gomez R, Ghezzi F, Yoon BH, Mazor M, Edwin SS, et al. A fetal systemic inflammatory response is followed by the spontaneous onset of preterm parturition. Am J Obstet Gynecol. 1998;179:186–93.10.1016/S0002-9378(98)70271-6Search in Google Scholar
[178] Gomez R, Romero R, Ghezzi F, Yoon BH, Mazor M, Berry SM. The fetal inflammatory response syndrome. Am J Obstet Gynecol. 1998;179:194–202.10.1016/S0002-9378(98)70272-8Search in Google Scholar
[179] Yoon BH, Romero R, Kim KS, Park JS, Ki SH, Kim BI, et al. A systemic fetal inflammatory response and the development of bronchopulmonary dysplasia. Am J Obstet Gynecol. 1999;181:773–9.10.1016/S0002-9378(99)70299-1Search in Google Scholar
[180] Dammann O, Leviton A. Role of the fetus in perinatal infection and neonatal brain damage. Curr Opin Pediatr. 2000;12:99–104.10.1097/00008480-200004000-00002Search in Google Scholar PubMed
[181] Dammann O, Kuban KC, Leviton A. Perinatal infection, fetal inflammatory response, white matter damage, and cognitive limitations in children born preterm. Ment Retard Dev Disabil Res Rev. 2002;8:46–50.10.1002/mrdd.10005Search in Google Scholar PubMed
[182] Romero R, Espinoza J, Goncalves LF, Gomez R, Medina L, Silva M, et al. Fetal cardiac dysfunction in preterm premature rupture of membranes. J Matern Fetal Neonatal Med. 2004;16:146–57.10.1080/jmf.16.3.146.157Search in Google Scholar
[183] Kim YM, Romero R, Chaiworapongsa T, Espinoza J, Mor G, Kim CJ. Dermatitis as a component of the fetal inflammatory response syndrome is associated with activation of Toll-like receptors in epidermal keratinocytes. Histopathology. 2006;49:506–14.10.1111/j.1365-2559.2006.02542.xSearch in Google Scholar PubMed PubMed Central
[184] Gotsch F, Romero R, Kusanovic JP, Mazaki-Tovi S, Pineles BL, Erez O, et al. The fetal inflammatory response syndrome. Clin Obstet Gynecol. 2007;50:652–83.10.1097/GRF.0b013e31811ebef6Search in Google Scholar PubMed
[185] Kim SK, Romero R, Chaiworapongsa T, Kusanovic JP, Mazaki-Tovi S, Mittal P, et al. Evidence of changes in the immunophenotype and metabolic characteristics (intracellular reactive oxygen radicals) of fetal, but not maternal, monocytes and granulocytes in the fetal inflammatory response syndrome. J Perinat Med. 2009;37:543–52.10.1515/JPM.2009.106Search in Google Scholar PubMed PubMed Central
[186] Malaeb S, Dammann O. Fetal inflammatory response and brain injury in the preterm newborn. J Child Neurol. 2009;24:1119–26.10.1177/0883073809338066Search in Google Scholar PubMed PubMed Central
[187] Romero R, Savasan ZA, Chaiworapongsa T, Berry SM, Kusanovic JP, Hassan SS, et al. Hematologic profile of the fetus with systemic inflammatory response syndrome. J Perinat Med. 2011;40:19–32.Search in Google Scholar
[188] Chaiworapongsa T, Romero R, Berry SM, Hassan SS, Yoon BH, Edwin S, et al. The role of granulocyte colony-stimulating factor in the neutrophilia observed in the fetal inflammatory response syndrome. J Perinat Med. 2011;39:653–66.10.1515/jpm.2011.072Search in Google Scholar PubMed PubMed Central
[189] Romero R, Soto E, Berry SM, Hassan SS, Kusanovic JP, Yoon BH, et al. Blood pH and gases in fetuses in preterm labor with and without systemic inflammatory response syndrome. J Matern Fetal Neonatal Med. 2012;25:1160–70.10.3109/14767058.2011.629247Search in Google Scholar PubMed PubMed Central
[190] Hofer N, Kothari R, Morris N, Muller W, Resch B. The fetal inflammatory response syndrome is a risk factor for morbidity in preterm neonates. Am J Obstet Gynecol. 2013;209:542 e1–e11.10.1016/j.ajog.2013.08.030Search in Google Scholar PubMed
[191] Kallapur SG, Presicce P, Rueda CM, Jobe AH, Chougnet CA. Fetal immune response to chorioamnionitis. Semin Reprod Med. 2014;32:56–67.10.1055/s-0033-1361823Search in Google Scholar PubMed PubMed Central
[192] Sosenko IR, Kallapur SG, Nitsos I, Moss TJ, Newnham JP, Ikegami M, et al. IL-1 alpha causes lung inflammation and maturation by direct effects on preterm fetal lamb lungs. Pediatr Res. 2006;60294–8.10.1203/01.pdr.0000233115.51309.d3Search in Google Scholar PubMed
[193] Polin RA. Systemic infection and brain injury in the preterm infant. Jornal de pediatria. 2008;84:188–91.10.2223/JPED.1784Search in Google Scholar PubMed
[194] Kemp MW, Saito M, Newnham JP, Nitsos I, Okamura K, Kallapur SG. Preterm birth, infection, and inflammation advances from the study of animal models. Reprod Sci. 2010;17:619–28.10.1177/1933719110373148Search in Google Scholar PubMed
[195] Kallapur SG, Kramer BW, Nitsos I, Pillow JJ, Collins JJ, Polglase GR, et al. Pulmonary and systemic inflammatory responses to intra-amniotic IL-1alpha in fetal sheep. Am J Physiol Lung Cellular Mol Physiol. 2011;301:L285–95.10.1152/ajplung.00446.2010Search in Google Scholar PubMed PubMed Central
[196] Wolfs TG, Kallapur SG, Polglase GR, Pillow JJ, Nitsos I, Newnham JP, et al. IL-1alpha mediated chorioamnionitis induces depletion of FoxP3+ cells and ileal inflammation in the ovine fetal gut. PloS one. 2011;6:e18355.10.1371/journal.pone.0018355Search in Google Scholar PubMed PubMed Central
[197] von Ehrenstein OS, Neta GI, Andrews W, Goldenberg R, Goepfert A, Zhang J. Child intellectual development in relation to cytokine levels in umbilical cord blood. Am J Epidemiol. 2012;175:1191–9.10.1093/aje/kwr393Search in Google Scholar PubMed PubMed Central
[198] O’Shea TM, Allred EN, Kuban KC, Dammann O, Paneth N, Fichorova R, et al. Elevated concentrations of inflammation-related proteins in postnatal blood predict severe developmental delay at 2 years of age in extremely preterm infants. J Pediatr. 2012;160:395–401 e4.10.1016/j.jpeds.2011.08.069Search in Google Scholar PubMed PubMed Central
[199] Bose CL, Laughon MM, Allred EN, O’Shea TM, Van Marter LJ, Ehrenkranz RA, et al. Systemic inflammation associated with mechanical ventilation among extremely preterm infants. Cytokine. 2013;61:315–22.10.1016/j.cyto.2012.10.014Search in Google Scholar PubMed PubMed Central
[200] Piantino JH, Schreiber MD, Alexander K, Hageman J. Culture negative sepsis and systemic inflammatory response syndrome in neonates. NeoReviews. 2013;14:e294.10.1542/neo.14-6-e294Search in Google Scholar
[201] Leviton A, Fichorova RN, O’Shea TM, Kuban K, Paneth N, Dammann O, et al. Two-hit model of brain damage in the very preterm newborn: small for gestational age and postnatal systemic inflammation. Pediatr Res. 2013;73:362–70.10.1038/pr.2012.188Search in Google Scholar PubMed PubMed Central
[202] Martin CR, Bellomy M, Allred EN, Fichorova RN, Leviton A. Systemic inflammation associated with severe intestinal injury in extremely low gestational age newborns. Fetal Pediatr Pathol. 2013;32:222–34.10.3109/15513815.2012.721477Search in Google Scholar PubMed PubMed Central
[203] Kuypers E, Jellema RK, Ophelders DR, Dudink J, Nikiforou M, Wolfs TG, et al. Effects of intra-amniotic lipopolysaccharide and maternal betamethasone on brain inflammation in fetal sheep. PloS one. 2013;8:e81644.10.1371/journal.pone.0081644Search in Google Scholar PubMed PubMed Central
[204] O’Shea TM, Shah B, Allred EN, Fichorova RN, Kuban KC, Dammann O, et al. Inflammation-initiating illnesses, inflammation-related proteins, and cognitive impairment in extremely preterm infants. Brain Behav Immun. 2013;29:104–12.10.1016/j.bbi.2012.12.012Search in Google Scholar PubMed PubMed Central
[205] Dammann O, Leviton A. Intermittent or sustained systemic inflammation and the preterm brain. Pediatr Res. 2014;75:376–80.10.1038/pr.2013.238Search in Google Scholar PubMed PubMed Central
[206] Kuban KC, O’Shea TM, Allred EN, Paneth N, Hirtz D, Fichorova RN, et al. Systemic inflammation and cerebral palsy risk in extremely preterm infants. J Child Neurol. 2014;29:1692–8.10.1177/0883073813513335Search in Google Scholar PubMed PubMed Central
[207] O’Shea TM, Joseph RM, Kuban KC, Allred EN, Ware J, Coster T, et al. Elevated blood levels of inflammation-related proteins are associated with an attention problem at age 24 mo in extremely preterm infants. Pediatr Res. 2014;75:781–7.10.1038/pr.2014.41Search in Google Scholar PubMed PubMed Central
[208] Kuban KC, O’Shea TM, Allred EN, Fichorova RN, Heeren T, Paneth N, et al. The breadth and type of systemic inflammation and the risk of adverse neurological outcomes in extremely low gestation newborns. Pediatr Neurol. 2015;52:42–8.10.1016/j.pediatrneurol.2014.10.005Search in Google Scholar PubMed PubMed Central
[209] Chiesa C, Pacifico L, Natale F, Hofer N, Osborn JF, Resch B. Fetal and early neonatal interleukin-6 response. Cytokine. 2015. [Epub ahead of print].10.1016/j.cyto.2015.03.015Search in Google Scholar PubMed
[210] DiGiulio DB, Gervasi MT, Romero R, Vaisbuch E, Mazaki-Tovi S, Kusanovic JP, et al. Microbial invasion of the amniotic cavity in pregnancies with small-for-gestational-age fetuses. J Perinat Med. 2010;38:495–502.10.1515/jpm.2010.076Search in Google Scholar PubMed PubMed Central
[211] Madan I, Romero R, Kusanovic JP, Mittal P, Chaiworapongsa T, Dong Z, et al. The frequency and clinical significance of intra-amniotic infection and/or inflammation in women with placenta previa and vaginal bleeding: an unexpected observation. J Perinat Med. 2010;38:275–9.10.1515/jpm.2010.001Search in Google Scholar PubMed PubMed Central
[212] Cruciani L, Romero R, Vaisbuch E, Kusanovic JP, Chaiworapongsa T, Mazaki-Tovi S, et al. Pentraxin 3 in amniotic fluid: a novel association with intra-amniotic infection and inflammation. J Perinat Med. 2010;38:161–71.10.1515/jpm.2009.141Search in Google Scholar PubMed PubMed Central
[213] Gervasi MT, Romero R, Bracalente G, Erez O, Dong Z, Hassan SS, et al. Midtrimester amniotic fluid concentrations of interleukin-6 and interferon-gamma-inducible protein-10: evidence for heterogeneity of intra-amniotic inflammation and associations with spontaneous early (<32 weeks) and late (>32 weeks) preterm delivery. J Perinat Med. 2012;40:329–43.10.1515/jpm-2012-0034Search in Google Scholar
[214] Gibbs RS, Dinsmoor MJ, Newton ER, Ramamurthy RS. A randomized trial of intrapartum versus immediate postpartum treatment of women with intra-amniotic infection. Obstet Gynecol. 1988;72:823–8.10.1097/00006250-198812000-00001Search in Google Scholar
[215] Chaiworapongsa T, Romero R, Kim JC, Kim YM, Blackwell SC, Yoon BH, et al. Evidence for fetal involvement in the pathologic process of clinical chorioamnionitis. Am J Obstet Gynecol. 2002;186:1178–82.10.1067/mob.2002.124042Search in Google Scholar
[216] Madsen-Bouterse SA, Romero R, Tarca AL, Kusanovic JP, Espinoza J, Kim CJ, et al. The transcriptome of the fetal inflammatory response syndrome. American journal of reproductive immunology. 2010;63:73–92.10.1111/j.1600-0897.2009.00791.xSearch in Google Scholar
[217] Vaisbuch E, Romero R, Gomez R, Kusanovic JP, Mazaki-Tovi S, Chaiworapongsa T, et al. An elevated fetal interleukin-6 concentration can be observed in fetuses with anemia due to Rh alloimmunization: implications for the understanding of the fetal inflammatory response syndrome. J Matern Fetal Neonatal Med. 2011;24:391–6.10.3109/14767058.2010.507294Search in Google Scholar
[218] Park JS, Romero R, Yoon BH, Moon JB, Oh SY, Han SY, et al. The relationship between amniotic fluid matrix metalloproteinase-8 and funisitis. Am J Obstet Gynecol. 2001;185:1156–61.10.1067/mob.2001.117679Search in Google Scholar
[219] Yoon BH, Romero R, Shim JY, Shim SS, Kim CJ, Jun JK. C-reactive protein in umbilical cord blood: a simple and widely available clinical method to assess the risk of amniotic fluid infection and funisitis. J Matern Fetal Neonatal Med. 2003;14:85–90.10.1080/jmf.14.2.85.90Search in Google Scholar
[220] Park CW, Lee SM, Park JS, Jun JK, Romero R, Yoon BH. The antenatal identification of funisitis with a rapid MMP-8 bedside test. J Perinat Med. 2008;36:497–502.10.1515/JPM.2008.079Search in Google Scholar
[221] Romero R, Ceska M, Avila C, Mazor M, Behnke E, Lindley I. Neutrophil attractant/activating peptide-1/interleukin-8 in term and preterm parturition. Am J Obstet Gynecol. 1991;165(4 Pt 1):813–20.10.1016/0002-9378(91)90422-NSearch in Google Scholar
[222] Cherouny PH, Pankuch GA, Romero R, Botti JJ, Kuhn DC, Demers LM, et al. Neutrophil attractant/activating peptide-1/interleukin-8: association with histologic chorioamnionitis, preterm delivery, and bioactive amniotic fluid leukoattractants. Am J Obstet Gynecol. 1993;169:1299–303.10.1016/0002-9378(93)90297-VSearch in Google Scholar
[223] Hsu CD, Meaddough E, Aversa K, Hong SF, Lu LC, Jones DC, et al. Elevated amniotic fluid levels of leukemia inhibitory factor, interleukin 6, and interleukin 8 in intra-amniotic infection. Am J Obstet Gynecol. 1998;179:1267–70.10.1016/S0002-9378(98)70144-9Search in Google Scholar
[224] Ghezzi F, Gomez R, Romero R, Yoon BH, Edwin SS, David C, et al. Elevated interleukin-8 concentrations in amniotic fluid of mothers whose neonates subsequently develop bronchopulmonary dysplasia. Eur J Obstet Gynecol Reprod Biol. 1998;78:5–10.10.1016/S0301-2115(97)00236-4Search in Google Scholar
[225] Figueroa R, Garry D, Elimian A, Patel K, Sehgal PB, Tejani N. Evaluation of amniotic fluid cytokines in preterm labor and intact membranes. J Matern Fetal Neonatal Med. 2005;18:241–7.10.1080/13506120500223241Search in Google Scholar
[226] Yoneda S, Sakai M, Sasaki Y, Shiozaki A, Hidaka T, Saito S. Interleukin-8 and glucose in amniotic fluid, fetal fibronectin in vaginal secretions and preterm labor index based on clinical variables are optimal predictive markers for preterm delivery in patients with intact membranes. J Obstet Gynaecol Res. 2007;33:38–44.10.1111/j.1447-0756.2007.00474.xSearch in Google Scholar
[227] Jacobsson B, Mattsby-Baltzer I, Hagberg H. Interleukin-6 and interleukin-8 in cervical and amniotic fluid: relationship to microbial invasion of the chorioamniotic membranes. BJOG: Int J Obstet Gynaec. 2005;112:719–24.10.1111/j.1471-0528.2005.00536.xSearch in Google Scholar
[228] Kacerovsky M, Drahosova M, Hornychova H, Pliskova L, Bolehovska R, Forstl M, et al. Value of amniotic fluid interleukin-8 for the prediction of histological chorioamnionitis in preterm premature rupture of membranes. Neuro Endocrinol Lett. 2009;30:733–8.Search in Google Scholar
[229] Keelan JA, Yang J, Romero RJ, Chaiworapongsa T, Marvin KW, Sato TA, et al. Epithelial cell-derived neutrophil-activating peptide-78 is present in fetal membranes and amniotic fluid at increased concentrations with intra-amniotic infection and preterm delivery. Biol Reprod. 2004;70:253–9.10.1095/biolreprod.103.016204Search in Google Scholar
[230] Nhan-Chang CL, Romero R, Kusanovic JP, Gotsch F, Edwin SS, Erez O, et al. A role for CXCL13 (BCA-1) in pregnancy and intra-amniotic infection/inflammation. J Matern Fetal Neonatal Med. 2008;21:763–75.10.1080/14767050802244946Search in Google Scholar
[231] Romero R, Quintero R, Emamian M, Wan M, Grzyboski C, Hobbins JC, et al. Arachidonate lipoxygenase metabolites in amniotic fluid of women with intra-amniotic infection and preterm labor. Am J Obstet Gynecol. 1987;157:1454–60.10.1016/S0002-9378(87)80243-0Search in Google Scholar
[232] Hamill N, Romero R, Gotsch F, Kusanovic JP, Edwin S, Erez O, et al. Exodus-1 (CCL20): evidence for the participation of this chemokine in spontaneous labor at term, preterm labor, and intrauterine infection. J Perinat Med. 2008;36:217–27.10.1515/JPM.2008.034Search in Google Scholar PubMed PubMed Central
[233] Mittal P, Romero R, Kusanovic JP, Edwin SS, Gotsch F, Mazaki-Tovi S, et al. CXCL6 (granulocyte chemotactic protein-2): a novel chemokine involved in the innate immune response of the amniotic cavity. Am J Reprod Immunol. 2008;60:246–57.10.1111/j.1600-0897.2008.00620.xSearch in Google Scholar PubMed PubMed Central
[234] Romero R, Salafia CM, Athanassiadis AP, Hanaoka S, Mazor M, Sepulveda W, et al. The relationship between acute inflammatory lesions of the preterm placenta and amniotic fluid microbiology. Am J Obstet Gynecol. 1992;166:1382–8.10.1016/0002-9378(92)91609-ESearch in Google Scholar
[235] Park HS, Romero R, Lee SM, Park CW, Jun JK, Yoon BH. Histologic chorioamnionitis is more common after spontaneous labor than after induced labor at term. Placenta. 2010;31:792–5.10.1016/j.placenta.2010.06.013Search in Google Scholar
[236] Lee SM, Lee KA, Kim SM, Park CW, Yoon BH. The risk of intra-amniotic infection, inflammation and histologic chorioamnionitis in term pregnant women with intact membranes and labor. Placenta. 2011;32:516–21.10.1016/j.placenta.2011.03.012Search in Google Scholar
[237] Mi Lee S, Romero R, Lee KA, Jin Yang H, Joon Oh K, Park CW, et al. The frequency and risk factors of funisitis and histologic chorioamnionitis in pregnant women at term who delivered after the spontaneous onset of labor. J Matern Fetal Neonatal Med. 2011;24:37–42.10.3109/14767058.2010.482622Search in Google Scholar
[238] Hillier SL, Witkin SS, Krohn MA, Watts DH, Kiviat NB, Eschenbach DA. The relationship of amniotic fluid cytokines and preterm delivery, amniotic fluid infection, histologic chorioamnionitis, and chorioamnion infection. Obstet Gynecol. 1993;81:941–8.Search in Google Scholar
[239] Kim CJ, Yoon BH, Park SS, Kim MH, Chi JG. Acute funisitis of preterm but not term placentas is associated with severe fetal inflammatory response. Hum Pathol. 2001;32:623–9.10.1053/hupa.2001.24992Search in Google Scholar
[240] Rogers BB, Alexander JM, Head J, McIntire D, Leveno KJ. Umbilical vein interleukin-6 levels correlate with the severity of placental inflammation and gestational age. Hum Pathol. 2002;33:335–40.10.1053/hupa.2002.32214Search in Google Scholar
[241] Lee J, Oh KJ, Park CW, Park JS, Jun JK, Yoon BH. The presence of funisitis is associated with a decreased risk for the development of neonatal respiratory distress syndrome. Placenta. 2011;32:235–40.10.1016/j.placenta.2010.11.006Search in Google Scholar
[242] Gugino LJ, Buerger PT, Wactawski-Wende J, Fisher J. Chorioamnionitis: the association between clinical and histological diagnosis. Primary Care Update Ob/Gyns. 1998;5:148.10.1016/S1068-607X(98)00026-2Search in Google Scholar
[243] Kim CJ, Yoon BH, Park SH, Chi JG. Histotopographic distribution of placental inflammation: analysis of 22 cases. J Korean Med Sci. 1998;13:519–24.10.3346/jkms.1998.13.5.519Search in Google Scholar PubMed PubMed Central
[244] Oh KJ, Park KH, Kim SN, Jeong EH, Lee SY, Yoon HY. Predictive value of intra-amniotic and serum markers for inflammatory lesions of preterm placenta. Placenta. 2011;32:732–6.10.1016/j.placenta.2011.07.080Search in Google Scholar PubMed
[245] Erdemir G, Kultursay N, Calkavur S, Zekioglu O, Koroglu OA, Cakmak B, et al. Histological chorioamnionitis: effects on premature delivery and neonatal prognosis. Pediatr Neonatol. 2013;54:267–74.10.1016/j.pedneo.2013.03.012Search in Google Scholar
[246] Park CW, Yoon BH, Kim SM, Park JS, Jun JK. The frequency and clinical significance of intra-amniotic inflammation defined as an elevated amniotic fluid matrix metalloproteinase-8 in patients with preterm labor and low amniotic fluid white blood cell counts. Obstet Gynecol Sci. 2013;56:167–75.10.5468/ogs.2013.56.3.167Search in Google Scholar
[247] Keenan WJ, Steichen JJ, Mahmood K, Altshuler G. Placental pathology compared with clinical outcome: a retrospective blind review. Am J Dis Child. 1977;131:1224–7.10.1001/archpedi.1977.02120240042009Search in Google Scholar
[248] Russell P. Inflammatory lesions of the human placenta, I: clinical significance of acute chorioamnionitis. Am J Diagn Gynecol Obstet. 1979;1:127–37.Search in Google Scholar
[249] Arias F, Victoria A, Cho K, Kraus F. Placental histology and clinical characteristics of patients with preterm premature rupture of membranes. Obstet Gynecol. 1997;89:265–71.10.1016/S0029-7844(96)00451-6Search in Google Scholar
[250] Ogunyemi D, Murillo M, Jackson U, Hunter N, Alperson B. The relationship between placental histopathology findings and perinatal outcome in preterm infants. J Matern Fetal Neonatal Med. 2003;13:102–9.10.1080/jmf.13.2.102.109Search in Google Scholar PubMed
[251] Dempsey E, Chen MF, Kokottis T, Vallerand D, Usher R. Outcome of neonates less than 30 weeks gestation with histologic chorioamnionitis. Am J Perinatol. 2005;22:155–9.10.1055/s-2005-865020Search in Google Scholar PubMed
[252] Andrews WW, Goldenberg RL, Faye-Petersen O, Cliver S, Goepfert AR, Hauth JC. The Alabama Preterm Birth study: polymorphonuclear and mononuclear cell placental infiltrations, other markers of inflammation, and outcomes in 23- to 32-week preterm newborn infants. Am J Obstet Gynecol. 2006;195:803–8.10.1016/j.ajog.2006.06.083Search in Google Scholar PubMed
[253] Veleminsky M, Jr., Pradna J, Veleminsky M, Sr., Tosner J. Relationship of amniotic-type placenta inflammation to pPROM, PROM and risk of early onset neonatal sepsis. Neuro Endocrinol Lett. 2008;29:447–50.Search in Google Scholar
[254] Moscuzza F, Belcari F, Nardini V, Bartoli A, Domenici C, Cuttano A, et al. Correlation between placental histopathology and fetal/neonatal outcome: chorioamnionitis and funisitis are associated to intraventricular haemorrage and retinopathy of prematurity in preterm newborns. Gynecol Endocrinol: Official J International Society of Gynecological Endocrinology. 2011;27:319v23.10.3109/09513590.2010.487619Search in Google Scholar PubMed
[255] Tsiartas P, Kacerovsky M, Musilova I, Hornychova H, Cobo T, Savman K, et al. The association between histological chorioamnionitis, funisitis and neonatal outcome in women with preterm prelabor rupture of membranes. J Matern Fetal Neonatal Med. 2013;26:1332–6.10.3109/14767058.2013.784741Search in Google Scholar PubMed
[256] Arayici S, Kadioglu Simsek G, Oncel MY, Eras Z, Canpolat FE, Oguz SS, et al. The effect of histological chorioamnionitis on the short-term outcome of preterm infants </=32 weeks: a single-center study. J Matern Fetal Neonatal Med. 2014;27:1129–33.10.3109/14767058.2013.850668Search in Google Scholar PubMed
[257] St Geme JW, Jr., Murray DL, Carter J, Hobel CJ, Leake RD, Anthony BF, et al. Perinatal bacterial infection after prolonged rupture of amniotic membranes: an analysis of risk and management. J Pediatr. 1984;104:608–13.10.1016/S0022-3476(84)80562-4Search in Google Scholar
[258] Hoang D, Charlagorla P, Salafia C, VanHorn S, Dygulska B, Narula P, et al. Histologic chorioamnionitis as a consideration in the management of newborns of febrile mothers. J Matern Fetal Neonatal Med. 2013;26:828–32.10.3109/14767058.2012.751368Search in Google Scholar
[259] Cuna A, Hakima L, Tseng YA, Fornier B, Islam S, Quintos-Alagheband ML, et al. Clinical dilemma of positive histologic chorioamnionitis in term newborn. Front Pediatr. 2014;2:27.10.3389/fped.2014.00027Search in Google Scholar
[260] Overbach AM, Daniel SJ, Cassady G. The value of umbilical cord histology in the management of potential perinatal infection. J Pediatr. 1970;76:22–31.10.1016/S0022-3476(70)80125-1Search in Google Scholar
[261] Cassell GH, Davis RO, Waites KB, Brown MB, Marriott PA, Stagno S, et al. Isolation of Mycoplasma hominis and Ureaplasma urealyticum from amniotic fluid at 16–20 weeks of gestation: potential effect on outcome of pregnancy. Sex Transm Dis. 1983;10(Suppl 4):294–302.Search in Google Scholar
[262] Gray DJ, Robinson HB, Malone J, Thomson RB, Jr. Adverse outcome in pregnancy following amniotic fluid isolation of Ureaplasma urealyticum. Prenat Diagn. 1992;12:111–7.10.1002/pd.1970120206Search in Google Scholar PubMed
[263] Horowitz S, Mazor M, Romero R, Horowitz J, Glezerman M. Infection of the amniotic cavity with Ureaplasma urealyticum in the midtrimester of pregnancy. J Reprod Med. 1995;40:375–9.Search in Google Scholar
[264] McCracken GH, Jr., Shinefield HR. Changes in the pattern of neonatal septicemia and meningitis. Am J Dis Child. 1966;112:33–9.10.1001/archpedi.1966.02090100069006Search in Google Scholar PubMed
[265] Seo K, McGregor JA, French JI. Preterm birth is associated with increased risk of maternal and neonatal infection. Obstet Gynecol. 1992;79:75–80.Search in Google Scholar
[266] Stoll BJ, Hansen NI, Adams-Chapman I, Fanaroff AA, Hintz SR, Vohr B, et al. Neurodevelopmental and growth impairment among extremely low-birth-weight infants with neonatal infection. J Am Med Assoc. 2004;292:2357–65.10.1001/jama.292.19.2357Search in Google Scholar PubMed
[267] Roman J, Fernandez F, Velasco F, Rojas R, Roldan MR, Torres A. Serum TNF levels in neonatal sepsis and septic shock. Acta Paediatrica. 1993;82:352–4.10.1111/j.1651-2227.1993.tb12695.xSearch in Google Scholar PubMed
[268] Atici A, Satar M, Cetiner S, Yaman A. Serum tumor necrosis factor-alpha in neonatal sepsis. Am J Perinatol. 1997;14:401–4.10.1055/s-2007-994168Search in Google Scholar PubMed
[269] Stout MJ, Conlon B, Landeau M, Lee I, Bower C, Zhao Q, et al. Identification of intracellular bacteria in the basal plate of the human placenta in term and preterm gestations. Am J Obstet Gynecol. 2013;208:226 e1–7.10.1016/j.ajog.2013.01.018Search in Google Scholar PubMed PubMed Central
[270] Kolaczkowska E, Kubes P. Neutrophil recruitment and function in health and inflammation. Nat Rev Immunol. 2013;13:159–75.10.1038/nri3399Search in Google Scholar PubMed
The authors stated that there are no conflicts of interest regarding the publication of this article.
©2016 by De Gruyter
Abstract
Objective: Neonates born to mothers with clinical chorioamnionitis at term are at an increased risk of infection. Acute subchorionitis, chorioamnionitis, and funisitis are considered placental histologic features consistent with acute inflammation according to the Society for Pediatric Pathology. The objectives of this study were to examine the performance of placental histologic features in the identification of: 1) microbial-associated intra-amniotic inflammation (intra-amniotic infection); and 2) fetal inflammatory response syndrome (FIRS).
Methods: This retrospective cohort study included women with the diagnosis of clinical chorioamnionitis at term (n=45), who underwent an amniocentesis to determine: 1) the presence of microorganisms using both cultivation and molecular biologic techniques [polymerase chain reaction (PCR) with broad range primers]; and 2) interleukin (IL)-6 concentrations by enzyme-linked immunosorbent assay (ELISA). The diagnostic performance (sensitivity, specificity, accuracy, and likelihood ratios) of placental histologic features consistent with acute inflammation was determined for the identification of microbial-associated intra-amniotic inflammation and FIRS.
Results: 1) The presence of acute histologic chorioamnionitis and funisitis was associated with the presence of proven intra-amniotic infection assessed by amniotic fluid analysis; 2) funisitis was also associated with the presence of FIRS; 3) the negative predictive value of acute funisitis ≥stage 2 for the identification of neonates born to mothers with intra-amniotic infection was <50%, and therefore, suboptimal to exclude fetal exposure to bacteria in the amniotic cavity; and 4) acute funisitis ≥stage 2 had a negative predictive value of 86.8% for the identification of FIRS in a population with a prevalence of 20%.
Conclusion: Acute histologic chorioamnionitis and funisitis are associated with intra-amniotic infection and the presence of FIRS. However, current pathologic methods have limitations in the identification of the fetus exposed to microorganisms present in the amniotic cavity. Further studies are thus required to determine whether molecular markers can enhance the performance of placental pathology in the identification of neonates at risk for neonatal sepsis.
Introduction
Clinical chorioamnionitis is a heterogeneous syndrome [1] characterized by maternal fever accompanied by at least two of the following signs: maternal or fetal tachycardia, maternal leukocytosis, uterine tenderness, or foul-smelling amniotic fluid [2–14]. This syndrome is associated with proven intra-amniotic infection in almost 60% of cases, and is a major risk factor for neonatal sepsis [12, 15–23]. The rapid and accurate diagnosis of maternal intra-amniotic infection is important to guide the management of neonates exposed to intrapartum fever [24–34]. The gold standard for the diagnosis of intra-amniotic infection is amniotic fluid analysis with the use of cultivation and molecular microbiologic techniques to identify the presence of bacteria [35–52] and to assess the inflammatory response [13, 35–37, 53–59].
When information about the amniotic fluid microbiology and inflammatory state is not available, pediatricians must rely on clinical risk factors (e.g., maternal fever, rupture of membranes, etc.) [26–28, 60], signs of neonatal sepsis and laboratory tests, such as neonatal white blood cell and differential counts [61–80], immature to mature ratio of neutrophils [77, 80–83], interleukin (IL)-6 [84–118], IL-8 [81, 91, 100, 101, 104, 106, 109, 113, 119], C-reactive protein (CRP) [68–70, 72, 78, 103, 104, 113, 118, 120–125], procalcitonin [118, 123, 124, 126–128], blood [26, 30, 82, 129–134], and cerebro-spinal fluid cultures [135–144], as well as other biomarkers. Despite intensive investigation, the accurate identification of early-onset sepsis in neonatology remains a conundrum [26–28, 32, 34, 145].
Examination of the placenta, the largest human biopsy, can provide information about fetal exposure to intra-amniotic inflammation or infection [146–169]. Chorionitis and acute histologic chorioamnionitis are histologic lesions that represent a maternal response to inflammatory stimuli in the amniotic cavity, such as bacteria, viruses and fungi, or non-infectious insults, such as danger signals (alarmins resulting from cell stress, apoptosis, and pyroptosis) [156, 158, 163, 170–173]. Inflammation of the umbilical cord or chorionic vessels represents a fetal response and is indicative of a fetus’s exposure to inflammatory stimuli before birth [154].
As early as 1959, Benirschke proposed that the examination of the umbilical cord using a frozen section could be a rapid and accurate method to identify newborns exposed to infection in utero [146]. Decades later, this idea has been revisited [174–176]. However, a major limitation of all clinical studies performed to date in patients with clinical chorioamnionitis at term is that the presence of bacteria in the amniotic cavity remains unknown, and therefore, accurate ascertainment of intra-amniotic infection is not feasible. The objective of the current study was to examine the diagnostic performance of placental histologic features of acute inflammation in the identification of: 1) microbial-associated intra-amniotic inflammation (also termed intra-amniotic infection), and 2) fetal inflammatory response syndrome (FIRS). The latter outcome was selected because there is evidence that both FIRS [98, 177–191] and neonatal systemic inflammation [192–209] are associated with adverse neonatal and infant outcomes.
Materials and methods
This retrospective cohort study included women with the diagnosis of clinical chorioamnionitis at term, who underwent an amniocentesis to identify microorganisms in the amniotic cavity. Patients were identified by searching the clinical database and Bank of Biological Samples of Wayne State University, the Detroit Medical Center, and the Perinatology Research Branch (NICHD/NIH/DHHS). The criteria for entry were: 1) singleton gestation, 2) gestational age of ≥37 weeks, 3) sufficient amniotic fluid obtained by transabdominal amniocenteses for molecular microbiologic studies, and 4) absence of fetal malformations. These patients were included in prior studies, which provide a detailed description of sample collection, microbiological studies, and determination of amniotic fluid IL-6 concentrations and other cytokines [1, 3, 9–11].
All patients provided written informed consent. The use of biological specimens as well as clinical and ultrasound data for research purposes was approved by the Institutional Review Boards of NICHD, Wayne State University, and Sótero del Río Hospital, Santiago, Chile.
Clinical definitions
Microbial invasion of the amniotic cavity was defined according to the results of amniotic fluid culture and PCR/ESI-MS (broad-range PCR coupled with electrospray ionization mass spectrometry) (Ibis® Technology, Athogen, Carlsbad, CA, USA) [1, 45–47, 210]. Microbial-associated intra-amniotic inflammation (also termed intra-amniotic infection) was diagnosed when microorganisms were identified in the amniotic fluid using cultivation or molecular microbiologic techniques and elevated amniotic fluid IL-6 concentrations (≥2.6 ng/mL), as described in detail elsewhere [1, 13, 35–37, 39, 50, 53, 54, 56–59, 211–213].
Clinical chorioamnionitis was diagnosed by the presence of maternal fever (temperature >37.8°C) accompanied by two or more of the following criteria: 1) maternal tachycardia (heart rate >100 beats/min), 2) uterine tenderness, 3) foul-smelling amniotic fluid, 4) fetal tachycardia (heart rate >160 beats/min), and 5) maternal leukocytosis (leukocyte count >15,000 cells/mm3) [2, 4–8, 12, 214]. FIRS was diagnosed when umbilical cord plasma IL-6 concentrations were >11 pg/mL [178, 187–189, 215–217].
Placental pathology
Tissue samples were obtained from each placenta – one roll from the chorioamniotic membranes and one from the umbilical cord. Two sections were taken from both the chorionic and basal plates. Tissues were formalin-fixed and embedded in paraffin. Five-micrometer-thick sections of tissue blocks were stained with hematoxylin and eosin, and the slides were examined by perinatal pathologists masked to clinical outcomes.
Histopathological changes of the placenta were defined according to the diagnostic criteria proposed by the Perinatal Section of the Society for Pediatric Pathology [156]. Histologic features associated with acute inflammation are acute subchorionitis, acute histologic chorioamnionitis (maternal response), and funisitis/acute chorionic vasculitis (fetal response). The definition and staging of acute histologic chorioamnionitis and acute funisitis are described below.
Placental histologic features consistent with acute inflammation (maternal response) were diagnosed based on the presence of inflammatory cells in the chorionic plate and/or in the chorioamniotic membranes [156].
Stage 1 (acute subchorionitis/acute chorionitis): accumulation of neutrophils in the subchorionic zone and/or in the chorionic trophoblast layer of the extraplacental membranes.
Stage 2 (acute chorioamnionitis): more than a few scattered neutrophils in the chorionic plate and membranous connective tissues and/or in the amnion.
Stage 3 (necrotizing chorioamnionitis): marked neutrophilic infiltrate with degenerating neutrophils (karyorrhexis), thickened eosinophilic amniotic basement membrane, and focal amniotic epithelial necrosis.
Acute funisitis was diagnosed by the presence of neutrophils in the wall of the umbilical vessels and/or the Wharton’s jelly, also using previously reported criteria [98, 154, 156, 157, 218–220].
Stage 1 (acute chorionic vasculitis/umbilical phlebitis/chorionic vasculitis): neutrophils are identified in the wall of any chorionic plate vessel or in the umbilical vein (few neutrophils are usually present in the Wharton’s jelly, but without aggregates or concentric bands of inflammatory cells).
Stage 2 (umbilical arteritis): neutrophils are seen in one or both of the umbilical arteries and/or in the umbilical vein.
Stage 3 (necrotizing funisitis): presence of neutrophils, cellular debris, and/or mineralization in a concentric band, ring, or halo around one or more umbilical vessel(s).
Statistical analysis
The Kolmogorov-Smirnov test was used to test whether data were normally distributed. Chi-square and Fisher’s exact tests were used for comparisons of proportions. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and likelihood ratios (+/−) were all calculated for the identification of microbial-associated intra-amniotic inflammation and FIRS. Statistical analysis was performed using SPSS 19 (IBM Corp, Armonk, NY, USA). A P-value <0.05 was considered statistically significant.
Results
Clinical characteristics of the study population
The descriptive characteristics of the study population stratified by the presence or absence of microbial-associated intra-amniotic inflammation (intra-amniotic infection) were previously reported [3]. Microorganisms most frequently identified in the amniotic cavity were Ureaplasma spp. and Gardnerella vaginalis [1]. Briefly, patients with clinical chorioamnionitis at term with microbial-associated intra-amniotic inflammation had a significantly higher median amniotic fluid white blood cell count, amniotic fluid IL-6, and umbilical cord plasma IL-6 concentration than those without microbial-associated intra-amniotic inflammation (P<0.001, P<0.001, and P=0.03, respectively) [3]. The frequencies of FIRS and acute inflammatory lesions of the placenta were also significantly greater in patients with clinical chorioamnionitis at term with microbial-associated intra-amniotic inflammation than in those without microbial-associated intra-amniotic inflammation [FIRS: 36% (9/25) vs. 5% (1/20), P=0.03; and acute inflammatory lesions of the placenta: 70.8% (17/24) vs. 25% (5/20), P=0.02] [3].
The frequency of neonates with FIRS was 22.2% (10/45). Among them, 90% (9/10) and 66.7% (6/9) were born to mothers with intra-amniotic infection and with placental histologic lesions consistent with acute amniotic fluid infection respectively, [acute subchorionitis/histologic chorioamnionitis (n=5) or inflammation of the umbilical cord (n=5)] (Table 1). Among neonates with FIRS, whose mothers had placental histologic features consistent with acute inflammation, 83% (5/6) had stage 2 acute histologic chorioamnionitis/funisitis (Table 1). The descriptions of clinical characteristics, bacteria isolated from the amniotic cavity, amniotic fluid and umbilical cord plasma IL-6 concentrations, as well as placental histologic lesions in mothers whose neonates had FIRS, are shown in Table 1.
Clinical characteristics, amniotic fluid interleukin-6 concentrations, microorganisms identified in the amniotic cavity, and placental histologic features consistent with acute inflammation in mothers whose neonates have fetal inflammatory response syndrome (FIRS) (n=10/45; 22.2%).
| No. | Organisms identified by cultivation | Organisms identified by PCR/ESI-MS | Microbial-associated intra-amniotic inflammation (intra-amniotic infection) | GA at delivery (weeks) | Amniotic fluid IL-6 concentration (ng/mL) | Umbilical cord plasma IL-6 concentration (pg/mL) | Maternal response to acute inflammation | Fetal response to acute inflammation |
|---|---|---|---|---|---|---|---|---|
| 1. | Peptostreptococcus spp. | Gardnerella vaginalis Abiotrophia defectiva | Yes | 41+1 | 97.1 | 170.85 | No | Umbilical arteritis |
| 2. | Fusobacterium spp. | Fusobacterium nucleatum/periodonticum | Yes | 37+4 | 118.35 | 103.01 | Acute chorioamnionitis | Umbilical arteritis |
| 3. | Ureaplasma urealyticum Streptococcus agalactiae | Ureaplasma urealyticum Gardnerella vaginalis | Yes | 40+5 | 83.19 | 14.13 | Acute chorioamnionitis | Umbilical arteritis |
| 4. | No | No | No | 40+3 | 109.19 | 12.14 | Acute chorioamnionitis | Umbilical arteritis |
| 5. | Ureaplasma urealyticum | Firmicute (Lactobacillus) | Yes | 41+4 | 14.12 | 101.09 | No | No |
| 6. | Ureaplasma urealyticum Enterococcus spp. Gardnerella vaginalis | Peptostreptococcus anaerobius Ureaplasma urealyticum Gardnerella vaginalis | Yes | 41+1 | 19.94 | 52.84 | No | No |
| 7. | Staphylococcus agalactiae Staphylococcus aureus | Staphylococcus agalactiae | Yes | 40+4 | 32.82 | 31.67 | Acute chorioamnionitis | Umbilical phlebitis/chorionic vasculitis |
| 8. | Staphylococcus agalactiae | Staphylococcus agalactiae | Yes | 39+4 | 10.45 | 14.78 | No | No |
| 9. | No | Acinetobacter spp. Pseudomonas aerunginosa | Yes | 40+4 | 18.41 | 12.38 | Acute subchorionitis/chorionitis | No |
| 10. | Mycoplasma hominis | Propionibacterium acnes | Yes | 38+4 | 74.08 | 32.99 | N/Aa | N/Aa |
aN/A=A placental pathology report was not available for 1 patient, PCR ESI/MS=broad-range PCR coupled with electrospray ionization mass spectrometry, GA=gestational age, IL=interleukin.
Microbial-associated intra-amniotic inflammation defined by the presence of bacteria in the amniotic cavity and intra-amniotic inflammation (IL-6 ≥2.6 ng/mL); fetal inflammatory response is defined by a concentration of umbilical cord plasma IL-6 >11 pg/mL.
Acute subchorionitis/chorionitis=maternal response to acute inflammation stage 1, Acute chorioamnionitis=maternal response to acute inflammation stage 2, Necrotizing chorioamnionitis and subacute chorioamnionitis=maternal response to acute inflammation stage 3, Umbilical phlebitis/chorionic vasculitis=acute funisitis stage 1, Umbilical arteritis=acute funisitis stage 2, Necrotizing funisitis=acute funisitis stage 3.
Overall, 33% (15/45) of neonates born to mothers with clinical chorioamnionitis had suspected neonatal sepsis. Among these neonates, 53.3% (8/15) and 20% (3/15) were exposed to intra-amniotic infection and intra-amniotic inflammation without detectable bacteria, respectively. The remaining 26.7% (4/15) were born to mothers who had no intra-amniotic inflammation. All neonates with suspected neonatal sepsis (diagnosis based on clinical signs and laboratory findings) had negative blood cultures for microorganisms.
Diagnostic performance
The diagnostic performance of placental histologic features consistent with acute inflammation for the identification of microbial-associated intra-amniotic inflammation (also termed intra-amniotic infection) is shown in Table 2. The sensitivity of placental histologic features of acute inflammation ranged from 16.7% to 70.8%. Specifically, acute histologic chorioamnionitis and funisitis ≥stage 2 had sensitivities of 25% (6/24) and 16.7% (4/24), respectively (Table 2). The PPV or NPV of placental histologic features associated with acute inflammation was fair (PPV: 60%–73.9%; NPV: 47.1%–66.7%) (Table 2). Overall, the accuracy of placental histologic features of acute inflammation for the identification of microbial-associated intra-amniotic inflammation only ranged from 50% to 70% (Table 2).
The diagnostic performance of placental histologic features consistent with acute inflammation for the identification of intra-amniotic infection (microbial-associated intra-amniotic inflammation) in patients with clinical chorioamnionitis at term (n=25/45; 55.56%).a
| Sensitivity (%) | Specificity (%) | Positive likelihood ratio (95% CI) | Negative likelihood ratio (95% CI) | Positive predictive value (%) | Negative predictive value (%) | Accuracy | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| % (n) | 95% CI | % (n) | 95% CI | % (n) | 95% CI | % (n) | 95% CI | ||||
| Acute subchorionitis, chorioamnionitis (n=22/44) | 66.7% (16/24) | (44.7–84.3) | 70.0% (14/20) | (45.7–88.0) | 2.2 (1.0–4.6) | 0.5 (0.3–0.9) | 72.7% (16/22) | (49.8–89.2) | 63.6% (14/22) | (40.7–82.8) | 68.2% (30/44) |
| Acute funisitis (n=13/44) | 33.3% (8/24) | (15.7–55.3) | 70.0% (14/20) | (45.7–91.3) | 1.3 (0.5–3.4) | 0.9 (0.6–1.3) | 61.5% (8/13) | (31.6–86.0) | 48.4% (15/31) | (30.2–66.9) | 52.3% (23/44) |
| Acute inflammatory histologic features of the placenta (n=23/44) | 70.8% (17/24) | (48.9–87.3) | 71.4% (15/21) | (47.8–88.0) | 2.4 (1.2–4.8) | 0.4 (0.2–0.8) | 73.9% (17/23) | (51.6–89.7) | 66.7% (17/21) | (43.0–85.4) | 70.5% (31/44) |
| Acute histologic chorioamnionitis ≥stage 2 (n=10/44) | 25.0% (6/24) | (9.8–46.7) | 80.0% (16/20) | (56.3–94.1) | 1.3 (0.4–3.8) | 0.9 (0.7–1.3) | 60.0% (6/10) | (26.4–87.6) | 47.1% (16/34) | (29.8–64.9) | 50% (22/44) |
| Acute funisitis ≥stage 2 (n=6/44) | 16.7% (4/24) | (4.8–37.4) | 90.0% (18/20) | (68.3–98.5) | 1.7 (0.3–8.2) | 0.9 (0.7–1.2) | 66.7% (4/6) | (22.7–94.7) | 47.4% (18/38) | (30.9–64.2) | 50% (22/44) |
aA placental pathology report was not available for 1 patient.
CI=confidence interval, intra-amniotic infection (microbial-associated intra-amniotic inflammation) is defined by the presence of bacteria in the amniotic cavity and intra-amniotic inflammation (IL-6≥2.6 ng/mL).
Acute subchorionitis/chorionitis=maternal response to acute inflammation stage 1, Acute chorioamnionitis=maternal response to acute inflammation stage 2, Necrotizing chorioamnionitis and subacute chorioamnionitis=maternal response to acute inflammation stage 3, Umbilical phlebitis/chorionic vasculitis=acute funisitis stage 1, Umbilical arteritis=acute funisitis stage 2, Necrotizing funisitis=acute funisitis stage 3.
Acute inflammatory histologic features of the placenta: acute subchorionitis, chorioamnionitis and/or acute funisitis.
The diagnostic performance of placental histologic lesions for the identification of FIRS is displayed in Table 3. The sensitivity and specificity ranged from 44.4% to 66.7% and 51.4% to 94.3%, respectively. Acute funisitis ≥stage 2 had the highest specificity (94.3%) followed by acute histologic chorioamnionitis ≥stage 2 (82.9%) when compared to other placental histologic lesions (Table 3). All placental histologic features had an NPV above 80%; however, the PPV ranged from 22.7% to 66.7% (Table 3). Acute funisitis ≥stage 2 had a positive likelihood ratio of 7.8 for the identification of FIRS.
The diagnostic performance of placental histologic features consistent with acute inflammation for the identification of fetal inflammatory response syndrome (FIRS) in patients with clinical chorioamnionitis at term (n=9/45; 20%).a
| Sensitivity (%) | Specificity (%) | Positive likelihood ratio (95% CI) | Negative likelihood ratio (95% CI) | Positive predictive value (%) | Negative predictive value (%) | Accuracy | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| % (n) | 95% CI | % (n) | 95% CI | % (n) | 95% CI | % (n) | 95% CI | ||||
| Acute subchorionitis, chorioamnionitis (n=22/44) | 55.6% (5/9) | (21.4–86.0) | 51.4% (18/35) | (34.0–68.6) | 1.1 (0.6–2.3) | 0.9 (0.4–1.9) | 22.7% (5/22) | (7.9–45.4) | 81.8% (18/22) | (59.7–94.7) | 52.3% (23/44) |
| Acute funisitis (n=13/44) | 55.6% (5/9) | (21.4–86.0) | 77.1% (27/35) | (59.9–89.6) | 2.4 (1.1–5.7) | 0.6 (0.3–1.2) | 38.5% (5/13) | (14.0–68.4) | 87.1% (27/31) | (70.2–96.3) | 72.7% (32/44) |
| Acute inflammatory histologic features of the placenta (n=23/44) | 66.7% (6/9) | (30.1–92.1) | 51.4% (18/35) | (34.0–68.6) | 1.4 (0.8–2.4) | 0.7 (0.2–1.7) | 26.1% (6/23) | (10.3–48.4) | 85.7% (18/21) | (63.6–96.8) | 54.5% (24/44) |
| Acute histologic chorioamnionitis ≥stage 2 (n=10/44) | 44.4% (4/9) | (13.9–78.6) | 82.9% (29/35) | (66.3–93.4) | 2.6 (0.9–7.3) | 0.7 (0.4–1.2) | 40.0% (4/10) | (12.4–73.6) | 85.3% (29/34) | (68.9–94.9) | 75.% (33/44) |
| Acute funisitis ≥stage 2 (n=6/44) | 44.4% (4/9) | (13.9–78.6) | 94.3% (33/35) | (80.8–99.1) | 7.8 (1.7–35.9) | 0.6 (0.3–1.1) | 66.7% (4/6) | (22.7–94.7) | 86.8% (33/38) | (71.9–95.5) | 72.7% (32/44) |
aA placental pathology report was not available for 1 patient.
CI=confidence interval, FIRS=fetal inflammatory response syndrome is defined by umbilical cord interleukin-6 concentration >11 pg/mL.
Acute subchorionitis/chorionitis=maternal response to acute inflammation stage 1, Acute chorioamnionitis=maternal response to acute inflammation stage 2, Necrotizing chorioamnionitis and subacute chorioamnionitis=maternal response to acute inflammation stage 3, Umbilical phlebitis/chorionic vasculitis=acute funisitis stage 1, Umbilical arteritis=acute funisitis stage 2, Necrotizing funisitis=acute funisitis stage 3.
Acute inflammatory histologic features of the placenta: acute subchorionitis, chorioamnionitis and/or acute funisitis.
The diagnostic indices of acute inflammatory histologic features of the placenta for the identification of intra-amniotic inflammation are shown in Table 4. The sensitivity and NPV for such placental histologic features ranged from 14.7% to 61.7%, and 23.7%–38.1%, respectively. The overall accuracy was <70% in the identification of intra-amniotic inflammation (Table 4).
The diagnostic performance of placental histologic features consistent with acute inflammation for the identification of intra-amniotic inflammation in patients with clinical chorioamnionitis at term (n=35/45; 77.8%).a
| Sensitivity (%) | Specificity (%) | Positive likelihood ratio (95% CI) | Negative likelihood ratio (95% CI) | Positive predictive value (%) | Negative predictive value (%) | Accuracy | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| % (n) | 95% CI | % (n) | 95% CI | % (n) | 95% CI | % (n) | 95% CI | ||||
| Acute subchorionitis, chorioamnionitis (n=22/44) | 58.8% (20/34) | (40.7–75.3) | 80% (8/10) | (44.4–98.9) | 2.9 (0.8–10.5) | 0.5 (0.3–0.9) | 90.9% (20/22) | (70.8–98.6) | 36.4% (8/22) | (17.2–59.3) | 63.6% (28/44) |
| Acute funisitis (n=13/44) | 32.4% (11/34) | (17.4–50.5) | 80% (8/10) | (44.4–96.9) | 1.6 (0.4–6.1) | 0.9 (0.6–1.3) | 84.6% (11/13) | (54.5.–97.6) | 25.8% (8/31) | (11.9–44.6) | 43.2% (19/44) |
| Acute inflammatory histologic features of the placenta (n=23/44) | 61.8% (21/34) | (43.6–77.8) | 80% (8/10) | (44.4–96.8) | 3.1 (0.9–10.9) | 0.5 (0.3–0.8) | 91.3% (21/23) | (71.9–98.7) | 38.1% (8/21) | (18.2–61.6) | 65.9% (29/44) |
| Acute histologic chorioamnionitis ≥stage 2 (n=10/44) | 23.5% (8/34) | (10.8–41.2) | 80% (8/10) | (44.4–96.9) | 1.2 (0.3–4.7) | 0.9 (0.7–1.4) | 80.0% (8/10) | (44.4–96.9) | 25.5% (8/34) | (10.8–41.2) | 36.4% (16/44) |
| Acute funisitis≥stage 2 (n=6/44) | 14.7 % (5/34) | (5.0–31.1) | 90% (9/10) | (55.5–98.3) | 1.5 (0.2–11.2) | 0.95 (0.7–1.2) | 88.3% (5/6) | (36.1–97.2) | 23.7% (9/38) | (11.5–40.3) | 34% (14/44) |
aA placental pathology report was not available for 1 patient.
CI=confidence interval, IL=interleukin, intra-amniotic inflammation is defined by amniotic fluid IL-6 concentration≥2.6 ng/mL.
Acute subchorionitis/chorionitis=maternal response to acute inflammation stage 1, Acute chorioamnionitis=maternal response to acute inflammation stage 2, Necrotizing chorioamnionitis and subacute chorioamnionitis=maternal response to acute inflammation stage 3, Umbilical phlebitis/chorionic vasculitis=acute funisitis stage 1, Umbilical arteritis=acute funisitis stage 2, Necrotizing funisitis=acute funisitis stage 3.
Acute inflammatory histologic features of the placenta: acute subchorionitis, chorioamnionitis and/or acute funisitis.
Discussion
Principal findings of the study
1) The presence of acute histologic chorioamnionitis and funisitis was associated with the presence of proven intra-amniotic infection assessed by amniotic fluid analysis; 2) funisitis was also associated with the presence of FIRS; 3) the NPV of funisitis ≥stage 2 for the identification of neonates born to mothers with intra-amniotic infection was <50%, and therefore suboptimal to exclude fetal exposure to bacteria in the amniotic cavity; and 4) funisitis ≥stage 2 had an NPV of 86.8% for the identification of FIRS in a population with a prevalence of 20%. Further studies are required to determine whether molecular markers can enhance the performance of placental pathology in the identification of neonates at risk for neonatal sepsis.
Acute histologic chorioamnionitis and funisitis: two different types of inflammatory responses and their relationship with microbial invasion of the amniotic cavity
Acute histologic chorioamnionitis or chorionitis consists of the infiltration of the chorion or chorioamniotic membranes by maternal neutrophils and, therefore, is a maternal host response to chemotactic products [156, 158, 163, 170–173]. The mechanism underlying neutrophil infiltration is the presence of high concentrations of neutrophil chemokines in the amniotic fluid, which would generate a gradient promoting the migration of the neutrophils from the decidua to the chorion, and subsequently, the amnion. The following chemotactic factors have been identified in the amniotic cavity of patients in preterm labor: IL-8 [43, 48, 221–228], neutrophil activating peptide [221, 222, 229], CXCL-13 [230], leukotriene B4 [231], epithelial cell-derived neutrophil-activating peptide-78 (ENA-78) [229], Exodus-1 (CCL20) [232], and CXCL-6 [233].
Funisitis represents a fetal inflammatory response, in which circulating fetal neutrophils migrate through the umbilical vein and artery with subsequent infiltration of the Wharton’s jelly [154, 156]. The first stage of funisitis is phlebitis, followed by arteritis, and then infiltration of the Wharton’s jelly [154, 156]. Chorionic vasculitis is the equivalent of funisitis in the chorionic plate of the placenta [154].
The presence of acute chorioamnionitis diagnosed by histologic examination of the placenta has traditionally been considered as evidence of intra-amniotic infection. Indeed, this lesion is classified by the Society for Pediatric Pathology as consistent with “amniotic fluid infection” [156]. The scientific basis for this infection has been that several studies have shown a strong relationship between the presence of bacteria in the amniotic fluid and acute inflammatory lesions of the placenta in patients who delivered within 48 h of amniocentesis with preterm labor and intact membranes. For example, in a population of patients with preterm labor and intact membranes, where the prevalence of microbial invasion of the amniotic cavity (determined with cultivation techniques) was 38% (35/92), the PPV of acute funisitis was 78.7% and that of acute chorioamnionitis was 71%. The NPV for microbial invasion of the amniotic cavity, defined as a positive amniotic fluid culture, ranged between 82% for funisitis and 86% for chorioamnionitis. Similar observations have been reported by other investigators [234]. In term gestations, acute histologic chorioamnionitis is more common in patients who underwent spontaneous labor than in those who delivered by cesarean section without labor [160, 235]. Moreover, the more advanced cervical dilatation at the time of a cesarean delivery, the greater the risk of acute histologic chorioamnionitis and microbial invasion of the amniotic cavity [236, 237]. Other studies have documented that acute histologic chorioamnionitis is associated with the presence of bacteria in the chorioamniotic space [150, 151, 238], although the strength of this association varies between term and preterm gestations [172, 173]. For example, in preterm birth, the frequency of funisitis ranges from 17% to 44.8% [98, 154, 218, 239–241], while at term, funisitis is present in only 6.1%–7.2% and 1.1%–4% of cases with and without labor, respectively [157, 160, 235, 237], and its frequency is higher in patients who have rupture of the membranes [157].
Placental histologic features associated with amniotic fluid infection for the identification of neonates at risk for infection/sepsis
Acute inflammatory histologic features of the placenta are associated with microbial invasion of the amniotic cavity, intra-amniotic inflammation/infection [46, 53, 98, 147–155, 157, 159–162, 165–169, 237, 238, 242–246], and neonatal infection [147–149, 155, 245, 247–256]. A previous study reported that adding placental inflammation (amnionitis) to clinical factors (gestational age, clinical chorioamnionitis, duration of labor, maternal age, race, and parity), which are used in the identification of neonatal infection, decreased the administration of antibiotics from 35% to 10% [257]. Hoang et al. also proposed to use the presence or absence of acute histologic chorioamnionitis to guide the duration of antimicrobial treatment in neonates at risk for sepsis [258].
We report herein that the acute inflammatory histologic features of the placenta could not accurately identify neonates born to mothers with intra-amniotic infection/inflammation, or neonates with FIRS/suspected sepsis. These findings are consistent with previous reports [164, 259]. Cuna et al. reported that the presence of acute histologic chorioamnionitis did not improve the predictive performance of other biomarkers for the identification of early-onset neonatal sepsis [259]. Moreover, in that study, none of the clinically stable term infants with acute histologic chorioamnionitis had early-onset neonatal sepsis, suggesting that isolated acute subchorionitis/histologic chorioamnionitis is not associated with adverse neonatal outcomes or the requirement of antimicrobial treatment [259]. Other investigators have also reported that 38% (53/139) of patients with “clinical chorioamnionitis” did not have histologic evidence of chorioamnionitis [153], and that only 4% of women at term gestation with acute histologic chorioamnionitis were found to have microorganisms in the placenta, despite using both cultivation and molecular microbiologic techniques [164]. These observations, as well as our findings reported herein, indicate that the conventional methods to examine the human placenta with hematoxylin and eosin have limitations in determining whether intra-amniotic infection was present or whether the inflammatory response in the umbilical cord can be attributed to microorganisms.
Acute funisitis is more specific but less sensitive than acute histologic chorioamnionitis for the identification of intra-amniotic infection [154]. This is easy to understand because acute chorioamnionitis merely reflects the presence of inflammatory stimuli in the amniotic cavity, such as microorganisms or danger signals [156, 158, 163, 170–173]. However, if the microorganisms in the amniotic cavity do not invade the human fetus, funisitis should not be present.
Funisitis was reported in 70% of preterm neonates with sepsis [260]. In contrast, in our previous study, which included 832 consecutive patients who delivered within 72 h of amniocentesis, funisitis was present in 17% of patients at term with positive amniotic fluid culture for bacteria [157], and none of these neonates had neonatal sepsis. Therefore, the clinical significance of funisitis in term and preterm gestations is substantially different [157, 239]. We have proposed that microbial invasion of the amniotic cavity during the course of spontaneous labor at term is short-lived, resulting in a more modest intra-amniotic inflammatory response, as well as a lower risk of FIRS, than in preterm gestation [41]. Intra-amniotic infection in patients presenting with an episode of preterm labor is likely to have occurred days or weeks before the initiation of labor and to have eventually led to the initiation of parturition with intact or ruptured membranes [261, 262]. Evidence in support of this is that patients with positive amniotic cultures for microorganisms at the time of genetic amniocentesis in the midtrimester eventually have preterm labor or preterm prelabor rupture of the membranes, which occurs frequently after a period of weeks [261–263]. Prolonged exposure to microorganisms in preterm gestations with subclinical microbial invasion of the amniotic cavity is more likely to result in fetal invasion. This would explain why congenital neonatal sepsis is more frequent in preterm than in term neonates [264, 265]. This view is consistent with our report about the differences in fetal IL-6 umbilical cord concentrations in response to microbial invasion of the amniotic cavity between term and preterm gestations [41].
The most likely explanation for the limitations of placental pathology to identify intra-amniotic infection is that the inflammation of the chorioamniotic membranes is a non-specific mechanism of host defense against danger signals of both microbial and non-microbial origin. We have recently reported that sterile intra-amniotic inflammation is common in patients with clinical chorioamnionitis at term [1], preterm labor with intact membranes [36, 39], preterm prelabor rupture of the membranes [35], and a short cervix [37]. These patients often exhibit evidence of acute chorioamnionitis in the absence of microorganisms in the amniotic fluid. The mechanisms responsible for the acute inflammatory response in the absence of microorganisms remain to be discovered, although we have previously proposed that alarmins could also play a role [39, 54]. The possibility that patients with sterile inflammation may have had an intra-amniotic infection controlled by the host, which leads to eradication of the microorganisms but an unresolved intra-amniotic inflammatory response, cannot be excluded.
In the current study, we focused on examining the relationship between placental histology and FIRS, because it is now evident that many of the complications of infection are mediated by the effects of systemic inflammation rather than the presence of organisms [177–209]. Indeed, patients could have asymptomatic bacteremia, which is transient and does not have adverse outcomes; yet, the combination of bacteria and systemic inflammation can lead to sepsis or septic shock [26–28, 32, 133]. In addition, the presence of FIRS or neonatal systemic inflammation is associated with adverse outcomes, even in the absence of detectable bacteria by cultivation and molecular microbiologic techniques, suggesting that an exaggerated inflammatory response plays a major role in neonatal outcomes [82, 98, 177–209, 266]. Previous studies have also shown a correlation between the concentrations of TNF-α in neonatal blood and the progression of neonatal sepsis to septic shock [267, 268].
Strengths and limitations
The major strength of this study is that both cultivation and molecular microbiologic techniques were used to identify microorganisms in the amniotic cavity; therefore, the diagnosis of microbial invasion was based on state-of-the-art methodologies. However, a larger sample size and replication are desirable. The use of molecular markers to identify the presence of microorganisms in the extrachorionic membranes, chorionic plate, and umbilical cord could be an important approach in providing morphologic evidence of the location of microorganisms in different sites. This could be accomplished using fluorescent in situ hybridization with probes aimed at identifying the conserved regions of the prokaryote genome, or alternatively, using stains for bacteria in tissues [161, 269]. Similarly, markers for neutrophil activation can improve the performance of conventional examination of the placenta [270].
Conclusion
Acute histologic chorioamnionitis and funisitis are associated with intra-amniotic infection and the presence of FIRS. Current pathologic methods have limitations in the identification of the fetus exposed to microorganisms present in the amniotic cavity. The use of molecular methods to identify bacteria in tissues and neutrophil activation may improve the performance of histologic examination of the placenta in the prediction of neonates at risk for sepsis.
Acknowledgments
This research was supported, in part, by the Perinatology Research Branch, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services (NICHD/NIH); and, in part, with Federal funds from NICHD, NIH under Contract No. HSN275201300006C.
References
[1] Romero R, Miranda J, Kusanovic JP, Chaiworapongsa T, Chaemsaithong P, Martinez A, et al. Clinical chorioamnionitis at term I: microbiology of the amniotic cavity using cultivation and molecular techniques. J Perinat Med. 2015;43:19–36.10.1515/jpm-2014-0249Search in Google Scholar
[2] Gibbs RS. Diagnosis of intra-amniotic infection. Semin Perinatol. 1977;1:71–7.Search in Google Scholar
[3] Romero R, Chaemsaithong P, Korzeniewski SJ, Kusanovic JP, Docheva N, Martinez-Varea A, et al. Clinical chorioamnionitis at term III: how well do clinical criteria perform in the identification of proven intra-amniotic infection? J Perinat Med. 2016;44:23–32.10.1515/jpm-2015-0044Search in Google Scholar
[4] Gibbs RS, Castillo MS, Rodgers PJ. Management of acute chorioamnionitis. Am J Obstet Gynecol. 1980;136:709–13.10.1016/0002-9378(80)90445-7Search in Google Scholar
[5] Gibbs RS, Blanco JD, St Clair PJ, Castaneda YS. Quantitative bacteriology of amniotic fluid from women with clinical intraamniotic infection at term. J Infect Dis. 1982;145:1–8.10.1093/infdis/145.1.1Search in Google Scholar PubMed
[6] MacVicar J. Chorioamnionitis. Clin Obstet Gynecol. 1970;13:272–90.10.1097/00003081-197006000-00005Search in Google Scholar PubMed
[7] Hollander D. Diagnosis of chorioamnionitis. Clin Obstet Gynecol. 1986;29:816–25.10.1097/00003081-198612000-00008Search in Google Scholar PubMed
[8] Newton ER. Chorioamnionitis and intraamniotic infection. Clin Obstet Gynecol. 1993;36:795–808.10.1097/00003081-199312000-00004Search in Google Scholar PubMed
[9] Romero R, Chaemsaithong P, Korzeniewski SJ, Tarca AL, Bhatti G, Xu Z, et al. Clinical chorioamnionitis at term II: the intra-amniotic inflammatory response. J Perinat Med. 2016;44:5–22.Search in Google Scholar
[10] Romero R, Chaemsaithong P, Docheva N, Korzeniewski SJ, Tarca AL, Bhatti G, et al. Clinical chorioamnionitis at term IV: the maternal plasma cytokine profile. J Perinat Med. 2016;44:77–98.Search in Google Scholar
[11] Romero R, Chaemsaithoing P, Docheva N, Korzeniewski SJ, Tarca AL, Bhatti G, et al. Clinical chorioamnionitis at term V: umbilical cord plasma cytokine profile in the context of a systemic maternal inflammatory response. J Perinat Med. 2016;44:53–76.Search in Google Scholar
[12] Tita AT, Andrews WW. Diagnosis and management of clinical chorioamnionitis. Clin Perinatol. 2010;37:339–54.10.1016/j.clp.2010.02.003Search in Google Scholar PubMed PubMed Central
[13] Romero R, Chaiworapongsa T, Savasan ZA, Hussein Y, Dong Z, Kusanovic JP, et al. Clinical chorioamnionitis is characterized by changes in the expression of the alarmin HMGB1 and one of its receptors, sRAGE. J Matern Fetal Neonatal Med. 2012;25:558–67.10.3109/14767058.2011.599083Search in Google Scholar PubMed PubMed Central
[14] Fishman SG, Gelber SE. Evidence for the clinical management of chorioamnionitis. Semin Fetal & Neonatal Medicine 2012;17:46–50.10.1016/j.siny.2011.09.002Search in Google Scholar PubMed
[15] Yoder PR, Gibbs RS, Blanco JD, Castaneda YS, St Clair PJ. A prospective, controlled study of maternal and perinatal outcome after intra-amniotic infection at term. Am J Obstet Gynecol. 1983;145:695–701.10.1016/0002-9378(83)90575-6Search in Google Scholar
[16] Yancey MK, Duff P, Kubilis P, Clark P, Frentzen BH. Risk factors for neonatal sepsis. Obstet Gynecol. 1996;87:188–94.10.1016/0029-7844(95)00402-5Search in Google Scholar
[17] Ladfors L, Tessin I, Mattsson LA, Eriksson M, Seeberg S, Fall O. Risk factors for neonatal sepsis in offspring of women with prelabor rupture of the membranes at 34–42 weeks. J Perinat Med. 1998;26:94–101.10.1515/jpme.1998.26.2.94Search in Google Scholar PubMed
[18] Alexander JM, McIntire DM, Leveno KJ. Chorioamnionitis and the prognosis for term infants. Obstet Gynecol. 1999;94:274–8.Search in Google Scholar
[19] Benitz WE, Gould JB, Druzin ML. Risk factors for early-onset group B streptococcal sepsis: estimation of odds ratios by critical literature review. Pediatrics. 1999;103:e77.10.1542/peds.103.6.e77Search in Google Scholar PubMed
[20] Volante E, Moretti S, Pisani F, Bevilacqua G. Early diagnosis of bacterial infection in the neonate. J Matern Fetal Neonatal Med. 2004;16(Suppl 2):13–6.10.1080/jmf.16.2.13.16Search in Google Scholar
[21] Rouse DJ, Landon M, Leveno KJ, Leindecker S, Varner MW, Caritis SN, et al. The Maternal-Fetal Medicine Units cesarean registry: chorioamnionitis at term and its duration-relationship to outcomes. Am J Obstet Gynecol. 2004;191:211–6.10.1016/j.ajog.2004.03.003Search in Google Scholar PubMed
[22] Uyemura A, Ameel B, Caughey A. 425. Outcomes of chorioamnionitis in term pregnancies. Am J Obstet Gynecol. 2014;210:S215.10.1016/j.ajog.2013.10.458Search in Google Scholar
[23] Pappas A, Kendrick DE, Shankaran S, Stoll BJ, Bell EF, Laptook AR, et al. Chorioamnionitis and early childhood outcomes among extremely low-gestational-age neonates. J Am Med Assoc Pediatr. 2014;168:137–47.10.1001/jamapediatrics.2013.4248Search in Google Scholar PubMed PubMed Central
[24] Qazi SA, Stoll BJ. Neonatal sepsis: a major global public health challenge. Pediatr infect Dis J. 2009;28(Suppl 1):S1–2.10.1097/INF.0b013e31819587a9Search in Google Scholar PubMed
[25] Ganatra HA, Stoll BJ, Zaidi AK. International perspective on early-onset neonatal sepsis. Clin Perinatol. 2010;37:501–23.10.1016/j.clp.2010.02.004Search in Google Scholar PubMed
[26] Polin RA. Management of neonates with suspected or proven early-onset bacterial sepsis. Pediatrics. 2012;129:1006–15.10.1542/peds.2012-0541Search in Google Scholar PubMed
[27] Puopolo KM. Response to the American Academy of Pediatrics, Committee on the Fetus and Newborn statement, “management of neonates with suspected or proven early-onset bacterial sepsis”. Pediatrics. 2012;130:e1054–5; author reply e5–7.10.1542/peds.2012-2302CSearch in Google Scholar PubMed
[28] Polin R. In reply, clinical report: management of neonates with suspected or proven early-onset bacterial sepsis. Pediatrics. 2012;130:e1055–7.Search in Google Scholar
[29] Bhatti M, Chu A, Hageman JR, Schreiber M, Alexander K. Future directions in the evaluation and management of neonatal sepsis. NeoReviews. 2012;13:e103–e10.10.1542/neo.13-2-e103Search in Google Scholar
[30] Camacho-Gonzalez A, Spearman PW, Stoll BJ. Neonatal infectious diseases: evaluation of neonatal sepsis. Pediatr Clin North Am. 2013;60:367–89.10.1016/j.pcl.2012.12.003Search in Google Scholar PubMed PubMed Central
[31] Brady MT, Polin RA. Prevention and management of infants with suspected or proven neonatal sepsis. Pediatrics. 2013;132:166–8.10.1542/peds.2013-1310Search in Google Scholar PubMed
[32] Polin RA, Watterberg K, Benitz W, Eichenwald E. The conundrum of early-onset sepsis. Pediatrics. 2014;133:1122–3.10.1542/peds.2014-0360Search in Google Scholar PubMed
[33] Shane AL, Stoll BJ. Neonatal sepsis: progress towards improved outcomes. J Infection. 2014;68(Suppl 1):S24–32.10.1016/j.jinf.2013.09.011Search in Google Scholar PubMed
[34] Benitz WE, Wynn JL, Polin RA. Reappraisal of guidelines for management of neonates with suspected early-onset sepsis. J Pediatr. 2015;166:1070–4.10.1016/j.jpeds.2014.12.023Search in Google Scholar PubMed PubMed Central
[35] Romero R, Miranda J, Chaemsaithong P, Chaiworapongsa T, Kusanovic JP, Dong Z, et al. Sterile and microbial-associated intra-amniotic inflammation in preterm prelabor rupture of membranes. J Matern Fetal Neonatal Med. 2014:1–16. [Epub ahead of print].10.3109/14767058.2014.958463Search in Google Scholar PubMed PubMed Central
[36] Romero R, Miranda J, Chaiworapongsa T, Chaemsaithong P, Gotsch F, Dong Z, et al. A novel molecular microbiologic technique for the rapid diagnosis of microbial invasion of the amniotic cavity and intra-amniotic infection in preterm labor with intact membranes. Am J Reprod Immunol. 2014;71:330–58.10.1111/aji.12189Search in Google Scholar PubMed PubMed Central
[37] Romero R, Miranda J, Chaiworapongsa T, Chaemsaithong P, Gotsch F, Dong Z, et al. Sterile intra-amniotic inflammation in asymptomatic patients with a sonographic short cervix: prevalence and clinical significance. J Matern Fetal Neonatal Med. 2014:1–17. [Epub ahead of print].10.3109/14767058.2014.954243Search in Google Scholar PubMed PubMed Central
[38] Romero R, Kadar N, Miranda J, Korzeniewski SJ, Schwartz AG, Chaemsaithong P, et al. The diagnostic performance of the Mass Restricted (MR) score in the identification of microbial invasion of the amniotic cavity or intra-amniotic inflammation is not superior to amniotic fluid interleukin-6. J Matern Fetal Neonatal Med. 2014;27:757–69.10.3109/14767058.2013.844123Search in Google Scholar PubMed PubMed Central
[39] Romero R, Miranda J, Chaiworapongsa T, Korzeniewski SJ, Chaemsaithong P, Gotsch F, et al. Prevalence and clinical significance of sterile intra-amniotic inflammation in patients with preterm labor and intact membranes. Am J Reprod Immunol. 2014;72:458–74.10.1111/aji.12296Search in Google Scholar PubMed PubMed Central
[40] Yoon BH, Romero R, Kim M, Kim EC, Kim T, Park JS, et al. Clinical implications of detection of Ureaplasma urealyticum in the amniotic cavity with the polymerase chain reaction. Am J Obstet Gynecol. 2000;183:1130–7.10.1067/mob.2000.109036Search in Google Scholar PubMed
[41] Yoon BH, Romero R, Moon J, Chaiworapongsa T, Espinoza J, Kim YM, et al. Differences in the fetal interleukin-6 response to microbial invasion of the amniotic cavity between term and preterm gestation. J Matern Fetal Neonatal Med. 2003;13:32–8.10.1080/jmf.13.1.32.38Search in Google Scholar PubMed
[42] Jacobsson B, Mattsby-Baltzer I, Andersch B, Bokstrom H, Holst RM, Nikolaitchouk N, et al. Microbial invasion and cytokine response in amniotic fluid in a Swedish population of women with preterm prelabor rupture of membranes. Acta Obstet Gynecol Scand. 2003;82:423–31.10.1034/j.1600-0412.2003.00157.xSearch in Google Scholar PubMed
[43] Jacobsson B, Mattsby-Baltzer I, Andersch B, Bokstrom H, Holst RM, Wennerholm UB, et al. Microbial invasion and cytokine response in amniotic fluid in a Swedish population of women in preterm labor. Acta Obstet Gynecol Scand. 2003;82:120–8.10.1034/j.1600-0412.2003.00047.xSearch in Google Scholar PubMed
[44] Kim M, Kim G, Romero R, Shim SS, Kim EC, Yoon BH. Biovar diversity of Ureaplasma urealyticum in amniotic fluid: distribution, intrauterine inflammatory response and pregnancy outcomes. J Perinat Med. 2003;31:146–52.10.1515/JPM.2003.020Search in Google Scholar PubMed
[45] DiGiulio DB, Romero R, Amogan HP, Kusanovic JP, Bik EM, Gotsch F, et al. Microbial prevalence, diversity and abundance in amniotic fluid during preterm labor: a molecular and culture-based investigation. PloS one. 2008;3:e3056.10.1371/journal.pone.0003056Search in Google Scholar PubMed PubMed Central
[46] DiGiulio DB, Romero R, Kusanovic JP, Gomez R, Kim CJ, Seok KS, et al. Prevalence and diversity of microbes in the amniotic fluid, the fetal inflammatory response, and pregnancy outcome in women with preterm pre-labor rupture of membranes. Am J Reprod Immunol. 2010;64:38–57.10.1111/j.1600-0897.2010.00830.xSearch in Google Scholar PubMed PubMed Central
[47] DiGiulio DB, Gervasi M, Romero R, Mazaki-Tovi S, Vaisbuch E, Kusanovic JP, et al. Microbial invasion of the amniotic cavity in preeclampsia as assessed by cultivation and sequence-based methods. J Perinat Med. 2010;38:503–13.10.1515/jpm.2010.078Search in Google Scholar PubMed PubMed Central
[48] Kacerovsky M, Celec P, Vlkova B, Skogstrand K, Hougaard DM, Cobo T, et al. Amniotic fluid protein profiles of intraamniotic inflammatory response to Ureaplasma spp. and other bacteria. PloS one. 2013;8:e60399.10.1371/journal.pone.0060399Search in Google Scholar PubMed PubMed Central
[49] Cobo T, Kacerovsky M, Jacobsson B. Amniotic fluid infection, inflammation, and colonization in preterm labor with intact membranes. Am J Obstet Gynecol. 2014;211:708.10.1016/j.ajog.2014.06.060Search in Google Scholar PubMed
[50] Kacerovsky M, Musilova I, Andrys C, Hornychova H, Pliskova L, Kostal M, et al. Prelabor rupture of membranes between 34 and 37 weeks: the intraamniotic inflammatory response and neonatal outcomes. Am J Obstet Gynecol. 2014;210:325 e1–e10.10.1016/j.ajog.2013.10.882Search in Google Scholar PubMed
[51] Romero R, Dey SK, Fisher SJ. Preterm labor: one syndrome, many causes. Science. 2014;345:760–5.10.1126/science.1251816Search in Google Scholar PubMed PubMed Central
[52] Allen-Daniels MJ, Serrano MG, Pflugner LP, Fettweis JM, Prestosa MA, Koparde VN, et al. Identification of a gene in Mycoplasma hominis associated with preterm birth and microbial burden in intraamniotic infection. Am J Obstet Gynecol. 2015. [Epub ahead of print].10.1016/j.ajog.2015.01.032Search in Google Scholar PubMed PubMed Central
[53] Yoon BH, Romero R, Moon JB, Shim SS, Kim M, Kim G, et al. Clinical significance of intra-amniotic inflammation in patients with preterm labor and intact membranes. Am J Obstet Gynecol. 2001;185:1130–6.10.1067/mob.2001.117680Search in Google Scholar PubMed
[54] Romero R, Chaiworapongsa T, Alpay Savasan Z, Xu Y, Hussein Y, Dong Z, et al. Damage-associated molecular patterns (DAMPs) in preterm labor with intact membranes and preterm PROM: a study of the alarmin HMGB1. J Matern Fetal Neonatal Med. 2011;24:1444–55.10.3109/14767058.2011.591460Search in Google Scholar PubMed PubMed Central
[55] Cobo T, Palacio M, Martinez-Terron M, Navarro-Sastre A, Bosch J, Filella X, et al. Clinical and inflammatory markers in amniotic fluid as predictors of adverse outcomes in preterm premature rupture of membranes. Am J Obstet Gynecol. 2011;205:126 e1–8.10.1016/j.ajog.2011.03.050Search in Google Scholar PubMed
[56] Chaemsaithong P, Romero R, Korzeniewski SJ, Dong Z, Yeo L, Hassan SS, et al. A point of care test for the determination of amniotic fluid interleukin-6 and the chemokine CXCL-10/IP-10. J Matern Fetal Neonatal Med. 2014:1–10.10.3109/14767058.2014.961417Search in Google Scholar PubMed PubMed Central
[57] Combs CA, Gravett M, Garite TJ, Hickok DE, Lapidus J, Porreco R, et al. Amniotic fluid infection, inflammation, and colonization in preterm labor with intact membranes. Am J Obstet Gynecol. 2014;210:125. e1–15.10.1016/j.ajog.2013.11.032Search in Google Scholar
[58] Chaemsaithong P, Romero R, Korzeniewski SJ, Dong Z, Martinez-Varea A, Yoon BH, et al. A Rapid interleukin-6 bedside test for the identification of intra-amniotic inflammation in preterm labor with intact membranes. J Matern Fetal Neonatal Med. 2015;23:1–11. [Epub ahead of print].10.3109/14767058.2015.1006620Search in Google Scholar
[59] Chaemsaithong P, Romero R, Korzeniewski SJ, Dong Z, Martinez-Varea A, Yoon BH, et al. A point of care test for interleukin-6 in amniotic fluid in preterm prelabor rupture of membrances: a step toward the early treatment of acute intra-amniotic inflammation/infection. J Matern Fetal Neonatal Med. 2015;23:1–8. [Epub ahead of print].10.3109/14767058.2015.1006621Search in Google Scholar
[60] Verani JR, McGee L, Schrag SJ, Division of Bacterial Diseases NCfI, Respiratory Diseases CfDC, Prevention. Prevention of perinatal group B streptococcal disease-revised guidelines from CDC, 2010. MMWR Recommendations and reports : Morbidity and mortality weekly report Recommendations and reports / Centers for Disease Control. 2010;59(RR-10):1–6.Search in Google Scholar
[61] Tollner U, Pohlandt F, Kleinhauer E. Neonatal infection and white blood cell count. Pediatrics. 1980;65:1196–7.10.1542/peds.65.6.1196Search in Google Scholar
[62] Philip AG. White blood cells and acute phase reactants in neonatal sepsis. Pediatrie. 1984;39:371–8.Search in Google Scholar
[63] Weinberg AG, Rosenfeld CR, Manroe BL, Browne R. Neonatal blood cell count in health and disease. II. Values for lymphocytes, monocytes, and eosinophils. J Pediatr. 1985;106:462–6.10.1016/S0022-3476(85)80681-8Search in Google Scholar
[64] Rozycki HJ, Stahl GE, Baumgart S. Impaired sensitivity of a single early leukocyte count in screening for neonatal sepsis. Pediatr Infect Dis J. 1987;6:440–2.10.1097/00006454-198705000-00004Search in Google Scholar
[65] Kumar A. Leukocyte studies in diagnosis of neonatal sepsis. J Pediatr. 1989;114:505–6.10.1016/S0022-3476(89)80585-2Search in Google Scholar
[66] Greenberg DN, Yoder BA. Changes in the differential white blood cell count in screening for group B streptococcal sepsis. Pediatr Infect Dis J. 1990;9:886–9.10.1097/00006454-199012000-00006Search in Google Scholar PubMed
[67] DaSilva O, Hammerberg O. Diagnostic value of leukocyte indices in late neonatal sepsis. Pediatr Infect Dis J. 1994;13:409–11.10.1097/00006454-199405000-00014Search in Google Scholar
[68] Berger C, Uehlinger J, Ghelfi D, Blau N, Fanconi S. Comparison of C-reactive protein and white blood cell count with differential in neonates at risk for septicaemia. Eur J Pediatr. 1995;154:138–44. .10.1007/BF01991918Search in Google Scholar PubMed
[69] Buck C, Pohlandt F. Accuracy of leukocyte indices and C-reactive protein for diagnosis of neonatal infection. Pediatr Infect Dis Journal. 1995;14:1119–20. .10.1097/00006454-199512000-00026Search in Google Scholar PubMed
[70] Da Silva O, Ohlsson A, Kenyon C. Accuracy of leukocyte indices and C-reactive protein for diagnosis of neonatal sepsis: a critical review. Pediatr Infect Dis Journal. 1995;14:362–6.10.1097/00006454-199505000-00005Search in Google Scholar PubMed
[71] Polinski C. The value of the white blood cell count and differential in the prediction of neonatal sepsis. Neonatal Network. 1996;15:13–23.Search in Google Scholar
[72] da Silva O, Ohlsson A. How accurate are leukocyte indices and C-reactive protein for diagnosis of neonatal sepsis? Paediatr Child Health. 1998;3:158–9.10.1093/pch/3.3.158Search in Google Scholar PubMed PubMed Central
[73] Faix RG. Utility of complete blood count and blood culture screening to diagnose neonatal sepsis in the asymptomatic at-risk newborn. J Pediatr. 2003;143:686–7.Search in Google Scholar
[74] Ottolini MC, Lundgren K, Mirkinson LJ, Cason S, Ottolini MG. Utility of complete blood count and blood culture screening to diagnose neonatal sepsis in the asymptomatic at risk newborn. Pediatr Infect Dis J. 2003;22:430–4.10.1097/01.inf.0000068206.11303.ddSearch in Google Scholar PubMed
[75] Hornik CP, Benjamin DK, Becker KC, Benjamin DK, Jr., Li J, Clark RH, et al. Use of the complete blood cell count in late-onset neonatal sepsis. Pediatr Infect Dis J. 2012;31:803–7.10.1097/INF.0b013e31825691e4Search in Google Scholar PubMed PubMed Central
[76] Resch B, Edlinger S, Muller W. White blood cell counts in neonatal early-onset sepsis. Pediatr Infect Dis J. 2012;31:540-1; author reply 1.10.1097/INF.0b013e31824e4740Search in Google Scholar PubMed
[77] Murphy K, Weiner J. Use of leukocyte counts in evaluation of early-onset neonatal sepsis. Pediatr Infect Dis J. 2012;31:16–9.10.1097/INF.0b013e31822ffc17Search in Google Scholar PubMed
[78] Mussap M. Laboratory medicine in neonatal sepsis and inflammation. J Matern Fetal Neonatal Med. 2012;25(Suppl 4): 32–4.10.3109/14767058.2012.715000Search in Google Scholar PubMed
[79] Hornik CP, Benjamin DK, Becker KC, Benjamin DK, Jr., Li J, Clark RH, et al. Use of the complete blood cell count in early-onset neonatal sepsis. Pediatr Infect Dis J. 2012;31:799–802.10.1097/INF.0b013e318256905cSearch in Google Scholar PubMed PubMed Central
[80] Makkar M, Gupta C, Pathak R, Garg S, Mahajan NC. Performance evaluation of hematologic scoring system in early diagnosis of neonatal sepsis. J Clin Neonat. 2013;2:25–9.10.4103/2249-4847.109243Search in Google Scholar PubMed PubMed Central
[81] Ng PC. Diagnostic markers of infection in neonates. Arch Dis Child Fetal Neonatal. 2004;89:F229–35.10.1136/adc.2002.023838Search in Google Scholar
[82] Shah BA, Padbury JF. Neonatal sepsis: an old problem with new insights. Virulence. 2014;5:170–8.10.4161/viru.26906Search in Google Scholar
[83] Soni S, Wadhwa N, Kumar R, Faridi MM. Use of immature-to-total-neutrophil ratio in early neonatal sepsis. Pediatr Infect Dis J. 2012;31:1101–2; author reply 2.10.1097/INF.0b013e31826108daSearch in Google Scholar
[84] Miller LC, Isa S, LoPreste G, Schaller JG, Dinarello CA. Neonatal interleukin-1 beta, interleukin-6, and tumor necrosis factor: cord blood levels and cellular production. J Pediatr. 1990;117:961–5.10.1016/S0022-3476(05)80145-3Search in Google Scholar
[85] Buck C, Bundschu J, Gallati H, Bartmann P, Pohlandt F. Interleukin-6: a sensitive parameter for the early diagnosis of neonatal bacterial infection. Pediatrics. 1994;93:54–8.10.1542/peds.93.1.54Search in Google Scholar
[86] Lehrnbecher T, Schrod L, Kraus D, Roos T, Martius J, von Stockhausen HB. Interleukin-6 and soluble interleukin-6 receptor in cord blood in the diagnosis of early onset sepsis in neonates. Acta Paediatrica. 1995;84:806–8.10.1111/j.1651-2227.1995.tb13761.xSearch in Google Scholar
[87] Lehrnbecher T, Schrod L, Rutsch P, Roos T, Martius J, von Stockhausen HB. Immunologic parameters in cord blood indicating early-onset sepsis. Biol Neonate. 1996;70:206–12.10.1159/000244366Search in Google Scholar
[88] Messer J, Eyer D, Donato L, Gallati H, Matis J, Simeoni U. Evaluation of interleukin-6 and soluble receptors of tumor necrosis factor for early diagnosis of neonatal infection. J Pediatr. 1996;129:574–80.10.1016/S0022-3476(96)70123-3Search in Google Scholar
[89] Singh B, Merchant P, Walker CR, Kryworuchko M, Diaz-Mitoma F. Interleukin-6 expression in cord blood of patients with clinical chorioamnionitis. Pediat Res. 1996;39:976–9.10.1203/00006450-199606000-00008Search in Google Scholar PubMed
[90] Smulian JC, Bhandari V, Campbell WA, Rodis JF, Vintzileos AM. Value of umbilical artery and vein levels of interleukin-6 and soluble intracellular adhesion molecule-1 as predictors of neonatal hematologic indices and suspected early sepsis. J Maternal Fetal Med. 1997;6:254–9.Search in Google Scholar
[91] Berner R, Niemeyer CM, Leititis JU, Funke A, Schwab C, Rau U, et al. Plasma levels and gene expression of granulocyte colony-stimulating factor, tumor necrosis factor-alpha, interleukin (IL)-1beta, IL-6, IL-8, and soluble intercellular adhesion molecule-1 in neonatal early onset sepsis. Pediatr Res. 1998;44:469–77.10.1203/00006450-199810000-00002Search in Google Scholar PubMed
[92] Weimann E, Rutkowski S, Reisbach G. G-CSF, GM-CSF and IL-6 levels in cord blood: diminished increase of G-CSF and IL-6 in preterms with perinatal infection compared to term neonates. J Perinat Med. 1998;26:211–8.10.1515/jpme.1998.26.3.211Search in Google Scholar PubMed
[93] Perenyi A, Johann-Liang R, Stavola JJ. Assessment of cord blood IL-6 levels as an indicator of neonatal sepsis. Am J Perinat. 1999;16:525–30.10.1055/s-1999-7282Search in Google Scholar PubMed
[94] Smulian JC, Vintzileos AM, Lai YL, Santiago J, Shen-Schwarz S, Campbell WA. Maternal chorioamnionitis and umbilical vein interleukin-6 levels for identifying early neonatal sepsis. J matern Fetal Med. 1999;8:88–94.Search in Google Scholar
[95] Silveira RC, Procianoy RS. Evaluation of interleukin-6, tumour necrosis factor-alpha and interleukin-1beta for early diagnosis of neonatal sepsis. Acta Paediatrica. 1999;88:647–50.10.1080/08035259950169314Search in Google Scholar PubMed
[96] Kashlan F, Smulian J, Shen-Schwarz S, Anwar M, Hiatt M, Hegyi T. Umbilical vein interleukin 6 and tumor necrosis factor alpha plasma concentrations in the very preterm infant. The Pediatr Infect Dis J. 2000;19:238–43.10.1097/00006454-200003000-00013Search in Google Scholar PubMed
[97] Mehr S, Doyle LW. Cytokines as markers of bacterial sepsis in newborn infants: a review. The Pediatr Infect Dis J. 2000;19:879–87.10.1097/00006454-200009000-00014Search in Google Scholar PubMed
[98] Yoon BH, Romero R, Park JS, Kim M, Oh SY, Kim CJ, et al. The relationship among inflammatory lesions of the umbilical cord (funisitis), umbilical cord plasma interleukin 6 concentration, amniotic fluid infection, and neonatal sepsis. Am J Obstet Gynecol. 2000;183:1124–9.10.1067/mob.2000.109035Search in Google Scholar PubMed
[99] Dollner H, Vatten L, Linnebo I, Zanussi GF, Laerdal A, Austgulen R. Inflammatory mediators in umbilical plasma from neonates who develop early-onset sepsis. Biol Neonate. 2001;80:41–7.10.1159/000047118Search in Google Scholar PubMed
[100] Krueger M, Nauck MS, Sang S, Hentschel R, Wieland H, Berner R. Cord blood levels of interleukin-6 and interleukin-8 for the immediate diagnosis of early-onset infection in premature infants. Biol Neonate. 2001;80:118–23.10.1159/000047130Search in Google Scholar PubMed
[101] Santana C, Guindeo MC, Gonzalez G, Garcia-Munoz F, Saavedra P, Domenech E. Cord blood levels of cytokines as predictors of early neonatal sepsis. Acta Paediatrica. 2001;90:1176–81.10.1111/j.1651-2227.2001.tb03250.xSearch in Google Scholar
[102] Dollner H, Vatten L, Halgunset J, Rahimipoor S, Austgulen R. Histologic chorioamnionitis and umbilical serum levels of pro-inflammatory cytokines and cytokine inhibitors. BJOG Int J Obstet Gynaec. 2002;109:534–9.10.1111/j.1471-0528.2002.01028.xSearch in Google Scholar
[103] Laborada G, Rego M, Jain A, Guliano M, Stavola J, Ballabh P, et al. Diagnostic value of cytokines and C-reactive protein in the first 24 hours of neonatal sepsis. Am Journal Perinat. 2003;20:491–501.10.1055/s-2003-45382Search in Google Scholar PubMed
[104] Santana Reyes C, Garcia-Munoz F, Reyes D, Gonzalez G, Dominguez C, Domenech E. Role of cytokines (interleukin-1beta, 6, 8, tumour necrosis factor-alpha, and soluble receptor of interleukin-2) and C-reactive protein in the diagnosis of neonatal sepsis. Acta Paediatrica. 2003;92:221–7.10.1111/j.1651-2227.2003.tb00530.xSearch in Google Scholar PubMed
[105] Hatzidaki E, Gourgiotis D, Manoura A, Korakaki E, Bossios A, Galanakis E, et al. Interleukin-6 in preterm premature rupture of membranes as an indicator of neonatal outcome. Acta Obstet Gynecol Scand. 2005;84:632–8.10.1111/j.0001-6349.2005.00747.xSearch in Google Scholar PubMed
[106] Ng PC, Lam HS. Diagnostic markers for neonatal sepsis. Curr Opin Pediatr. 2006;18:125–31.10.1097/01.mop.0000193293.87022.4cSearch in Google Scholar PubMed
[107] Tasci Y, Dilbaz B, Uzmez Onal B, Caliskan E, Dilbaz S, Doganci L, et al. The value of cord blood interleukin-6 levels for predicting chorioamnionitis, funisitis and neonatal infection in term premature rupture of membranes. Eur J Obstet Gynecol Reprod Biol. 2006;128:34–9.10.1016/j.ejogrb.2005.11.049Search in Google Scholar PubMed
[108] Arnon S, Litmanovitz I. Diagnostic tests in neonatal sepsis. Curr Opin Infect Dis. 2008;21:223–7.10.1097/QCO.0b013e3282fa15ddSearch in Google Scholar PubMed
[109] Veleminsky M, Jr., Stransky P, Veleminsky M, Sr., Tosner J. Relationship of IL-6, IL-8, TNF and sICAM-1 levels to PROM, pPROM, and the risk of early-onset neonatal sepsis. Neuroendocrinol Lett. 2008;29:303–11.Search in Google Scholar
[110] Prinsen JH, Baranski E, Posch H, Tober K, Gerstmeyer A. Interleukin-6 as diagnostic marker for neonatal sepsis: determination of Access IL-6 cutoff for newborns. Clin Lab. 2008;54:179–83.Search in Google Scholar
[111] Cancelier AC, Petronilho F, Reinke A, Constantino L, Machado R, Ritter C, et al. Inflammatory and oxidative parameters in cord blood as diagnostic of early-onset neonatal sepsis: a case-control study. Pediatric Critical Care Medicine : A Journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies. 2009;10:467–71.10.1097/PCC.0b013e318198b0e3Search in Google Scholar PubMed
[112] Cernada M, Badia N, Modesto V, Alonso R, Mejias A, Golombek S, et al. Cord blood interleukin-6 as a predictor of early-onset neonatal sepsis. Acta Paediatrica. 2012;101:e203-7.10.1111/j.1651-2227.2011.02577.xSearch in Google Scholar PubMed
[113] Fan Y, Yu JL. Umbilical blood biomarkers for predicting early-onset neonatal sepsis. World J Pediatr. 2012;8:101–8.10.1007/s12519-012-0347-3Search in Google Scholar PubMed
[114] Hassanein SM, El-Farrash RA, Hafez HM, Hassanin OM, Abd El Rahman NA. Cord blood interleukin-6 and neonatal morbidities among preterm infants with PCR-positive Ureaplasma urealyticum. J Matern Fetal Neonatal Med. 2012;25:2106–10.10.3109/14767058.2012.678435Search in Google Scholar PubMed
[115] Cobo T, Kacerovsky M, Andrys C, Drahosova M, Musilova I, Hornychova H, et al. Umbilical cord blood IL-6 as predictor of early-onset neonatal sepsis in women with preterm prelabour rupture of membranes. PloS one. 2013;8:e69341.10.1371/journal.pone.0069341Search in Google Scholar PubMed PubMed Central
[116] Prashant A, Vishwanath P, Kulkarni P, Sathya Narayana P, Gowdara V, Nataraj SM, et al. Comparative assessment of cytokines and other inflammatory markers for the early diagnosis of neonatal sepsis-a case control study. PloS one. 2013;8:e68426.10.1371/journal.pone.0068426Search in Google Scholar PubMed PubMed Central
[117] Sorokin Y, Romero R, Mele L, Iams JD, Peaceman AM, Leveno KJ, et al. Umbilical cord serum interleukin-6, C-reactive protein, and myeloperoxidase concentrations at birth and association with neonatal morbidities and long-term neurodevelopmental outcomes. Am J Perinat. 2014;31:717–26.Search in Google Scholar
[118] Su H, Chang SS, Han CM, Wu KY, Li MC, Huang CY, et al. Inflammatory markers in cord blood or maternal serum for early detection of neonatal sepsis-a systemic review and meta-analysis. J Perinat: Official J California Perinatal Association. 2014;34:268–74.10.1038/jp.2013.186Search in Google Scholar PubMed
[119] Berner R, Tuxen B, Clad A, Forster J, Brandis M. Elevated gene expression of interleukin-8 in cord blood is a sensitive marker for neonatal infection. Eur J Pediat. 2000;159:205–10.10.1007/s004310050051Search in Google Scholar PubMed
[120] Sabel KG, Wadsworth C. C-reactive protein (CRP) in early diagnosis of neonatal septicemia. Acta Paediatrica Scand. 1979;68:825–31.Search in Google Scholar
[121] Hindocha P, Campbell CA, Gould JD, Wojciechowski A, Wood CB. Serial study of C reactive protein in neonatal septicaemia. Arch Dis Child. 1984;59:435–8.10.1136/adc.59.5.435Search in Google Scholar PubMed PubMed Central
[122] Mishra UK, Jacobs SE, Doyle LW, Garland SM. Newer approaches to the diagnosis of early onset neonatal sepsis. Arch Dis Child Fetal Neonat. 2006;91:F208–12.10.1136/adc.2004.064188Search in Google Scholar PubMed PubMed Central
[123] Joram N, Boscher C, Denizot S, Loubersac V, Winer N, Roze JC, et al. Umbilical cord blood procalcitonin and C reactive protein concentrations as markers for early diagnosis of very early onset neonatal infection. Arch Dis Child Fetal Neonat. 2006;91:F65–6.10.1136/adc.2005.074245Search in Google Scholar PubMed PubMed Central
[124] Kordek A, Halasa M, Podraza W. Early detection of an early onset infection in the neonate based on measurements of procalcitonin and C-reactive protein concentrations in cord blood. Clin Chem Lab Med. 2008;46:1143–8.10.1515/CCLM.2008.214Search in Google Scholar PubMed
[125] Howman RA, Charles AK, Jacques A, Doherty DA, Simmer K, Strunk T, et al. Inflammatory and haematological markers in the maternal, umbilical cord and infant circulation in histological chorioamnionitis. PloS one. 2012;7:e51836.10.1371/journal.pone.0051836Search in Google Scholar PubMed PubMed Central
[126] Janota J, Stranak Z, Belohlavkova S, Mudra K, Simak J. Postnatal increase of procalcitonin in premature newborns is enhanced by chorioamnionitis and neonatal sepsis. Eur J Clin Invest. 2001;31:978–83.10.1046/j.1365-2362.2001.00912.xSearch in Google Scholar PubMed
[127] Kordek A, Giedrys-Kalemba S, Pawlus B, Podraza W, Czajka R. Umbilical cord blood serum procalcitonin concentration in the diagnosis of early neonatal infection. J Perinat: Official J California Perinatal Association. 2003;23:148–53.10.1038/sj.jp.7210885Search in Google Scholar
[128] Llorente E, Prieto B, Cardo L, Avello N, Alvarez FV. Umbilical cord blood serum procalcitonin by Time-Resolved Amplified Cryptate Emission (TRACE) technology: reference values of a potential marker of vertically transmitted neonatal sepsis. Clin Chem Lab Med. 2007;45:1531–5.10.1515/CCLM.2007.304Search in Google Scholar
[129] Dietzman DE, Fischer GW, Schoenknecht FD. Neonatal Escherichia coli septicemia-bacterial counts in blood. J Pediat. 1974;85:128–30.10.1016/S0022-3476(74)80308-2Search in Google Scholar
[130] Polin JI, Knox I, Baumgart S, Campman E, Mennuti MT, Polin RA. Use of umbilical cord blood culture for detection of neonatal bacteremia. Obstet Gynecol. 1981;57:233–7.Search in Google Scholar
[131] Neal PR, Kleiman MB, Reynolds JK, Allen SD, Lemons JA, Yu PL. Volume of blood submitted for culture from neonates. J Clin Microbiol. 1986;24:353–6.10.1128/jcm.24.3.353-356.1986Search in Google Scholar
[132] Kellogg JA, Ferrentino FL, Goodstein MH, Liss J, Shapiro SL, Bankert DA. Frequency of low level bacteremia in infants from birth to two months of age. Pediat Infect Dis J. 1997;16: 381–5.10.1097/00006454-199704000-00009Search in Google Scholar
[133] Polin RA. The “ins and outs” of neonatal sepsis. J Pediatr. 2003;143:3–4.10.1016/S0022-3476(03)00271-3Search in Google Scholar
[134] Connell TG, Rele M, Cowley D, Buttery JP, Curtis N. How reliable is a negative blood culture result? Volume of blood submitted for culture in routine practice in a children’s hospital. Pediatrics. 2007;119:891–6.10.1542/peds.2006-0440Search in Google Scholar PubMed
[135] Hendricks-Munoz KD, Shapiro DL. The role of the lumbar puncture in the admission sepsis evaluation of the premature infant. J Perinat: Official J California Perinatal Association. 1990;10:60–4.Search in Google Scholar
[136] Wiswell TE, Baumgart S, Gannon CM, Spitzer AR. No lumbar puncture in the evaluation for early neonatal sepsis: will meningitis be missed? Pediatrics. 1995;95:803–6.Search in Google Scholar
[137] Kumar P, Sarkar S, Narang A. Role of routine lumbar puncture in neonatal sepsis. J Paediatr Child H. 1995;31:8–10.10.1111/j.1440-1754.1995.tb02902.xSearch in Google Scholar PubMed
[138] McIntyre P, Isaacs D. Lumbar puncture in suspected neonatal sepsis. J Paediatr Child H. 1995;31:1–2.10.1111/j.1440-1754.1995.tb02899.xSearch in Google Scholar PubMed
[139] Beeram M, Oltorf C, Cipriani C. Lumbar puncture in the evaluation for early neonatal sepsis. Pediatrics. 1996;97(6 Pt 1):930; author reply -1.10.1542/peds.97.6.930Search in Google Scholar
[140] Tierney AJ, Finer NN. Lumbar puncture in the evaluation for early neonatal sepsis. Pediatrics. 1996;97(6 Pt 1):929–30.10.1542/peds.97.6.929bSearch in Google Scholar
[141] Stoll BJ, Hansen N, Fanaroff AA, Wright LL, Carlo WA, Ehrenkranz RA, et al. To tap or not to tap: high likelihood of meningitis without sepsis among very low birth weight infants. Pediatrics. 2004;113:1181–6.10.1542/peds.113.5.1181Search in Google Scholar
[142] Ray B, Mangalore J, Harikumar C, Tuladhar A. Is lumbar puncture necessary for evaluation of early neonatal sepsis? Arch Dis Child. 2006;91:1033–5.10.1136/adc.2006.105106Search in Google Scholar
[143] Garges HP, Moody MA, Cotten CM, Smith PB, Tiffany KF, Lenfestey R, et al. Neonatal meningitis: what is the correlation among cerebrospinal fluid cultures, blood cultures, and cerebrospinal fluid parameters? Pediatrics. 2006;117:1094–100.10.1542/peds.2005-1132Search in Google Scholar
[144] Mhanna MJ, Alesseh H, Gori A, Aziz HF. Cerebrospinal fluid values in very low birth weight infants with suspected sepsis at different ages. Pediatric Critical Care Medicine: A Journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies. 2008;9:294–8.10.1097/01.PCC.0b013e31816c6e12Search in Google Scholar
[145] Kiser C, Nawab U, McKenna K, Aghai ZH. Role of guidelines on length of therapy in chorioamnionitis and neonatal sepsis. Pediatrics. 2014;133:992–8.10.1542/peds.2013-2927Search in Google Scholar
[146] Benirschke K, Clifford SH. Intrauterine bacterial infection of the newborn infant: frozen sections of the cord as an aid to early detection. J Pediatr. 1959;54:11–8.10.1016/S0022-3476(59)80031-7Search in Google Scholar
[147] Olding L. Value of placentitis as a sign of intrauterine infection in human subjects. Acta Pathol Microbiol Scand A. 1970;78:256–64.10.1111/j.1699-0463.1970.tb03300.xSearch in Google Scholar PubMed
[148] Zhang JM, Kraus FT, Aquino TI. Chorioamnionitis: a comparative histologic, bacteriologic, and clinical study. Int J Gynecol Pathol. 1985;4:1–10.10.1097/00004347-198501000-00001Search in Google Scholar
[149] Svensson L, Ingemarsson I, Mardh PA. Chorioamnionitis and the isolation of microorganisms from the placenta. Obstet Gynecol. 1986;67:403–9.Search in Google Scholar
[150] Hillier SL, Martius J, Krohn M, Kiviat N, Holmes KK, Eschenbach DA. A case-control study of chorioamnionic infection and histologic chorioamnionitis in prematurity. N Engl J Med. 1988;319:972–8.10.1056/NEJM198810133191503Search in Google Scholar PubMed
[151] Hillier SL, Krohn MA, Kiviat NB, Watts DH, Eschenbach DA. Microbiologic causes and neonatal outcomes associated with chorioamnion infection. Am J Obstet Gynecol. 1991;165(4 Pt 1):955–61.10.1016/0002-9378(91)90447-YSearch in Google Scholar
[152] van Hoeven KH, Anyaegbunam A, Hochster H, Whitty JE, Distant J, Crawford C, et al. Clinical significance of increasing histologic severity of acute inflammation in the fetal membranes and umbilical cord. Pediatr Pathol Lab Med. 1996;16:731–44.10.3109/15513819609169300Search in Google Scholar
[153] Smulian JC, Shen-Schwarz S, Vintzileos AM, Lake MF, Ananth CV. Clinical chorioamnionitis and histologic placental inflammation. Obstet Gynecol. 1999;94:1000–5.Search in Google Scholar
[154] Pacora P, Chaiworapongsa T, Maymon E, Kim YM, Gomez R, Yoon BH, et al. Funisitis and chorionic vasculitis: the histological counterpart of the fetal inflammatory response syndrome. J Matern Fetal Neonatal Med. 2002;11:18–25.10.1080/jmf.11.1.18.25Search in Google Scholar
[155] Rhone SA, Magee F, Remple V, Money D. The association of placental abnormalities with maternal and neonatal clinical findings: a retrospective cohort study. J Obstet Gynaecol Can. 2003;25:123–8.10.1016/S1701-2163(16)30208-0Search in Google Scholar
[156] Redline RW, Heller D, Keating S, Kingdom J. Placental diagnostic criteria and clinical correlation-a workshop report. Placenta. 2005;26(Suppl A):S114–7.10.1016/j.placenta.2005.02.009Search in Google Scholar PubMed
[157] Lee SE, Romero R, Kim CJ, Shim SS, Yoon BH. Funisitis in term pregnancy is associated with microbial invasion of the amniotic cavity and intra-amniotic inflammation. J Matern Fetal Neonatal Med. 2006;19:693–7.10.1080/14767050600927353Search in Google Scholar PubMed
[158] Redline RW. Inflammatory responses in the placenta and umbilical cord. Semin Fetal Neonatal Med. 2006;11:296–301.10.1016/j.siny.2006.02.011Search in Google Scholar PubMed
[159] Lee SE, Romero R, Jung H, Park CW, Park JS, Yoon BH. The intensity of the fetal inflammatory response in intraamniotic inflammation with and without microbial invasion of the amniotic cavity. Am J Obstet Gynecol. 2007;197:294 e1–6.10.1016/j.ajog.2007.07.006Search in Google Scholar PubMed
[160] Seong HS, Lee SE, Kang JH, Romero R, Yoon BH. The frequency of microbial invasion of the amniotic cavity and histologic chorioamnionitis in women at term with intact membranes in the presence or absence of labor. Am J Obstet Gynecol. 2008;199:375 e1–5.10.1016/j.ajog.2008.06.040Search in Google Scholar PubMed PubMed Central
[161] Kim MJ, Romero R, Gervasi MT, Kim JS, Yoo W, Lee DC, et al. Widespread microbial invasion of the chorioamniotic membranes is a consequence and not a cause of intra-amniotic infection. Lab Invest. 2009;89:924–36.10.1038/labinvest.2009.49Search in Google Scholar PubMed PubMed Central
[162] Park CW, Moon KC, Park JS, Jun JK, Romero R, Yoon BH. The involvement of human amnion in histologic chorioamnionitis is an indicator that a fetal and an intra-amniotic inflammatory response is more likely and severe: clinical implications. Placenta. 2009;30:56–61.10.1016/j.placenta.2008.09.017Search in Google Scholar PubMed PubMed Central
[163] Redline RW. Inflammatory response in acute chorioamnionitis. Semin Fetal Neonatal Med. 2012;17:20–5.10.1016/j.siny.2011.08.003Search in Google Scholar PubMed
[164] Roberts DJ, Celi AC, Riley LE, Onderdonk AB, Boyd TK, Johnson LC, et al. Acute histologic chorioamnionitis at term: nearly always noninfectious. PloS one. 2012;7:e31819.10.1371/journal.pone.0031819Search in Google Scholar PubMed PubMed Central
[165] Lee SM, Park JW, Kim BJ, Park CW, Park JS, Jun JK, et al. Acute histologic chorioamnionitis is a risk factor for adverse neonatal outcome in late preterm birth after preterm premature rupture of membranes. PloS one. 2013;8:e79941.10.1371/journal.pone.0079941Search in Google Scholar PubMed PubMed Central
[166] Park CW, Yoon BH, Kim SM, Park JS, Jun JK. Which is more important for the intensity of intra-amniotic inflammation between total grade or involved anatomical region in preterm gestations with acute histologic chorioamnionitis? Obstet Gynecol Sci. 2013;56:227–33.10.5468/ogs.2013.56.4.227Search in Google Scholar PubMed PubMed Central
[167] Park CW, Yoon BH, Park JS, Jun JK. A fetal and an intra-amniotic inflammatory response is more severe in preterm labor than in preterm PROM in the context of funisitis: unexpected observation in human gestations. PloS one. 2013;8:e62521.10.1371/journal.pone.0062521Search in Google Scholar PubMed PubMed Central
[168] Kim SM, Romero R, Park JW, Oh KJ, Jun JK, Yoon BH. The relationship between the intensity of intra-amniotic inflammation and the presence and severity of acute histologic chorioamnionitis in preterm gestation. J Matern Fetal Neonatal Med. 2014:1–10. [Epub ahead of print].10.3109/14767058.2014.961009Search in Google Scholar PubMed PubMed Central
[169] Park CW, Kim SM, Park JS, Jun JK, Yoon BH. Fetal, amniotic and maternal inflammatory responses in early stage of ascending intrauterine infection, inflammation restricted to chorio-decidua, in preterm gestation. J Matern Fetal Neonatal Med. 2014;27:98–105.10.3109/14767058.2013.806898Search in Google Scholar PubMed
[170] Murtha AP, Auten R, Herbert WN. Apoptosis in the chorion laeve of term patients with histologic chorioamnionitis. Infect Dis Obstet Gynecol. 2002;10:93–6.10.1155/S106474490200008XSearch in Google Scholar PubMed PubMed Central
[171] George RB, Kalich J, Yonish B, Murtha AP. Apoptosis in the chorion of fetal membranes in preterm premature rupture of membranes. Am J Perinat. 2008;25:29–32.10.1055/s-2007-1004828Search in Google Scholar PubMed
[172] Menon R, Taylor RN, Fortunato SJ. Chorioamnionitis-a complex pathophysiologic syndrome. Placenta. 2010;31:113–20.10.1016/j.placenta.2009.11.012Search in Google Scholar
[173] Conti N, Torricelli M, Voltolini C, Vannuccini S, Clifton VL, Bloise E, et al. Term histologic chorioamnionitis: a heterogeneous condition. Eur J Obstet Gynecol Reprod Biol. 2015;188:34–8.10.1016/j.ejogrb.2015.02.034Search in Google Scholar
[174] Mendilcioglu I, Kilicarslan B, Gurkan Zorlu C, Karaveli S, Uner M, Trak B. Placental biopsy by frozen section: does it have a role in evaluation of fetal well-being? Aust NZ J Obstet Gynaecol. 2003;43:433–7.10.1046/j.0004-8666.2003.00128.xSearch in Google Scholar
[175] Beaudet L, Karuri S, Lau J, Magee F, Lee SK, von Dadelszen P. Placental pathology and clinical outcomes in a cohort of infants admitted to a neonatal intensive care unit. J Obstet Gynaecol Can. 2007;29:315–23.10.1016/S1701-2163(16)32431-8Search in Google Scholar
[176] Mahe E, Hamid J, Terry J, Jansen JW, Bourgeois J, Arredondo-Marin J. Frozen section of placental membranes and umbilical cord: an aid to early postpartum diagnosis of intra-amniotic infection. Am J Clin Pathol. 2014;142:202–8.10.1309/AJCPYN70DLUFFDVPSearch in Google Scholar
[177] Romero R, Gomez R, Ghezzi F, Yoon BH, Mazor M, Edwin SS, et al. A fetal systemic inflammatory response is followed by the spontaneous onset of preterm parturition. Am J Obstet Gynecol. 1998;179:186–93.10.1016/S0002-9378(98)70271-6Search in Google Scholar
[178] Gomez R, Romero R, Ghezzi F, Yoon BH, Mazor M, Berry SM. The fetal inflammatory response syndrome. Am J Obstet Gynecol. 1998;179:194–202.10.1016/S0002-9378(98)70272-8Search in Google Scholar
[179] Yoon BH, Romero R, Kim KS, Park JS, Ki SH, Kim BI, et al. A systemic fetal inflammatory response and the development of bronchopulmonary dysplasia. Am J Obstet Gynecol. 1999;181:773–9.10.1016/S0002-9378(99)70299-1Search in Google Scholar
[180] Dammann O, Leviton A. Role of the fetus in perinatal infection and neonatal brain damage. Curr Opin Pediatr. 2000;12:99–104.10.1097/00008480-200004000-00002Search in Google Scholar PubMed
[181] Dammann O, Kuban KC, Leviton A. Perinatal infection, fetal inflammatory response, white matter damage, and cognitive limitations in children born preterm. Ment Retard Dev Disabil Res Rev. 2002;8:46–50.10.1002/mrdd.10005Search in Google Scholar PubMed
[182] Romero R, Espinoza J, Goncalves LF, Gomez R, Medina L, Silva M, et al. Fetal cardiac dysfunction in preterm premature rupture of membranes. J Matern Fetal Neonatal Med. 2004;16:146–57.10.1080/jmf.16.3.146.157Search in Google Scholar
[183] Kim YM, Romero R, Chaiworapongsa T, Espinoza J, Mor G, Kim CJ. Dermatitis as a component of the fetal inflammatory response syndrome is associated with activation of Toll-like receptors in epidermal keratinocytes. Histopathology. 2006;49:506–14.10.1111/j.1365-2559.2006.02542.xSearch in Google Scholar PubMed PubMed Central
[184] Gotsch F, Romero R, Kusanovic JP, Mazaki-Tovi S, Pineles BL, Erez O, et al. The fetal inflammatory response syndrome. Clin Obstet Gynecol. 2007;50:652–83.10.1097/GRF.0b013e31811ebef6Search in Google Scholar PubMed
[185] Kim SK, Romero R, Chaiworapongsa T, Kusanovic JP, Mazaki-Tovi S, Mittal P, et al. Evidence of changes in the immunophenotype and metabolic characteristics (intracellular reactive oxygen radicals) of fetal, but not maternal, monocytes and granulocytes in the fetal inflammatory response syndrome. J Perinat Med. 2009;37:543–52.10.1515/JPM.2009.106Search in Google Scholar PubMed PubMed Central
[186] Malaeb S, Dammann O. Fetal inflammatory response and brain injury in the preterm newborn. J Child Neurol. 2009;24:1119–26.10.1177/0883073809338066Search in Google Scholar PubMed PubMed Central
[187] Romero R, Savasan ZA, Chaiworapongsa T, Berry SM, Kusanovic JP, Hassan SS, et al. Hematologic profile of the fetus with systemic inflammatory response syndrome. J Perinat Med. 2011;40:19–32.Search in Google Scholar
[188] Chaiworapongsa T, Romero R, Berry SM, Hassan SS, Yoon BH, Edwin S, et al. The role of granulocyte colony-stimulating factor in the neutrophilia observed in the fetal inflammatory response syndrome. J Perinat Med. 2011;39:653–66.10.1515/jpm.2011.072Search in Google Scholar PubMed PubMed Central
[189] Romero R, Soto E, Berry SM, Hassan SS, Kusanovic JP, Yoon BH, et al. Blood pH and gases in fetuses in preterm labor with and without systemic inflammatory response syndrome. J Matern Fetal Neonatal Med. 2012;25:1160–70.10.3109/14767058.2011.629247Search in Google Scholar PubMed PubMed Central
[190] Hofer N, Kothari R, Morris N, Muller W, Resch B. The fetal inflammatory response syndrome is a risk factor for morbidity in preterm neonates. Am J Obstet Gynecol. 2013;209:542 e1–e11.10.1016/j.ajog.2013.08.030Search in Google Scholar PubMed
[191] Kallapur SG, Presicce P, Rueda CM, Jobe AH, Chougnet CA. Fetal immune response to chorioamnionitis. Semin Reprod Med. 2014;32:56–67.10.1055/s-0033-1361823Search in Google Scholar PubMed PubMed Central
[192] Sosenko IR, Kallapur SG, Nitsos I, Moss TJ, Newnham JP, Ikegami M, et al. IL-1 alpha causes lung inflammation and maturation by direct effects on preterm fetal lamb lungs. Pediatr Res. 2006;60294–8.10.1203/01.pdr.0000233115.51309.d3Search in Google Scholar PubMed
[193] Polin RA. Systemic infection and brain injury in the preterm infant. Jornal de pediatria. 2008;84:188–91.10.2223/JPED.1784Search in Google Scholar PubMed
[194] Kemp MW, Saito M, Newnham JP, Nitsos I, Okamura K, Kallapur SG. Preterm birth, infection, and inflammation advances from the study of animal models. Reprod Sci. 2010;17:619–28.10.1177/1933719110373148Search in Google Scholar PubMed
[195] Kallapur SG, Kramer BW, Nitsos I, Pillow JJ, Collins JJ, Polglase GR, et al. Pulmonary and systemic inflammatory responses to intra-amniotic IL-1alpha in fetal sheep. Am J Physiol Lung Cellular Mol Physiol. 2011;301:L285–95.10.1152/ajplung.00446.2010Search in Google Scholar PubMed PubMed Central
[196] Wolfs TG, Kallapur SG, Polglase GR, Pillow JJ, Nitsos I, Newnham JP, et al. IL-1alpha mediated chorioamnionitis induces depletion of FoxP3+ cells and ileal inflammation in the ovine fetal gut. PloS one. 2011;6:e18355.10.1371/journal.pone.0018355Search in Google Scholar PubMed PubMed Central
[197] von Ehrenstein OS, Neta GI, Andrews W, Goldenberg R, Goepfert A, Zhang J. Child intellectual development in relation to cytokine levels in umbilical cord blood. Am J Epidemiol. 2012;175:1191–9.10.1093/aje/kwr393Search in Google Scholar PubMed PubMed Central
[198] O’Shea TM, Allred EN, Kuban KC, Dammann O, Paneth N, Fichorova R, et al. Elevated concentrations of inflammation-related proteins in postnatal blood predict severe developmental delay at 2 years of age in extremely preterm infants. J Pediatr. 2012;160:395–401 e4.10.1016/j.jpeds.2011.08.069Search in Google Scholar PubMed PubMed Central
[199] Bose CL, Laughon MM, Allred EN, O’Shea TM, Van Marter LJ, Ehrenkranz RA, et al. Systemic inflammation associated with mechanical ventilation among extremely preterm infants. Cytokine. 2013;61:315–22.10.1016/j.cyto.2012.10.014Search in Google Scholar PubMed PubMed Central
[200] Piantino JH, Schreiber MD, Alexander K, Hageman J. Culture negative sepsis and systemic inflammatory response syndrome in neonates. NeoReviews. 2013;14:e294.10.1542/neo.14-6-e294Search in Google Scholar
[201] Leviton A, Fichorova RN, O’Shea TM, Kuban K, Paneth N, Dammann O, et al. Two-hit model of brain damage in the very preterm newborn: small for gestational age and postnatal systemic inflammation. Pediatr Res. 2013;73:362–70.10.1038/pr.2012.188Search in Google Scholar PubMed PubMed Central
[202] Martin CR, Bellomy M, Allred EN, Fichorova RN, Leviton A. Systemic inflammation associated with severe intestinal injury in extremely low gestational age newborns. Fetal Pediatr Pathol. 2013;32:222–34.10.3109/15513815.2012.721477Search in Google Scholar PubMed PubMed Central
[203] Kuypers E, Jellema RK, Ophelders DR, Dudink J, Nikiforou M, Wolfs TG, et al. Effects of intra-amniotic lipopolysaccharide and maternal betamethasone on brain inflammation in fetal sheep. PloS one. 2013;8:e81644.10.1371/journal.pone.0081644Search in Google Scholar PubMed PubMed Central
[204] O’Shea TM, Shah B, Allred EN, Fichorova RN, Kuban KC, Dammann O, et al. Inflammation-initiating illnesses, inflammation-related proteins, and cognitive impairment in extremely preterm infants. Brain Behav Immun. 2013;29:104–12.10.1016/j.bbi.2012.12.012Search in Google Scholar PubMed PubMed Central
[205] Dammann O, Leviton A. Intermittent or sustained systemic inflammation and the preterm brain. Pediatr Res. 2014;75:376–80.10.1038/pr.2013.238Search in Google Scholar PubMed PubMed Central
[206] Kuban KC, O’Shea TM, Allred EN, Paneth N, Hirtz D, Fichorova RN, et al. Systemic inflammation and cerebral palsy risk in extremely preterm infants. J Child Neurol. 2014;29:1692–8.10.1177/0883073813513335Search in Google Scholar PubMed PubMed Central
[207] O’Shea TM, Joseph RM, Kuban KC, Allred EN, Ware J, Coster T, et al. Elevated blood levels of inflammation-related proteins are associated with an attention problem at age 24 mo in extremely preterm infants. Pediatr Res. 2014;75:781–7.10.1038/pr.2014.41Search in Google Scholar PubMed PubMed Central
[208] Kuban KC, O’Shea TM, Allred EN, Fichorova RN, Heeren T, Paneth N, et al. The breadth and type of systemic inflammation and the risk of adverse neurological outcomes in extremely low gestation newborns. Pediatr Neurol. 2015;52:42–8.10.1016/j.pediatrneurol.2014.10.005Search in Google Scholar PubMed PubMed Central
[209] Chiesa C, Pacifico L, Natale F, Hofer N, Osborn JF, Resch B. Fetal and early neonatal interleukin-6 response. Cytokine. 2015. [Epub ahead of print].10.1016/j.cyto.2015.03.015Search in Google Scholar PubMed
[210] DiGiulio DB, Gervasi MT, Romero R, Vaisbuch E, Mazaki-Tovi S, Kusanovic JP, et al. Microbial invasion of the amniotic cavity in pregnancies with small-for-gestational-age fetuses. J Perinat Med. 2010;38:495–502.10.1515/jpm.2010.076Search in Google Scholar PubMed PubMed Central
[211] Madan I, Romero R, Kusanovic JP, Mittal P, Chaiworapongsa T, Dong Z, et al. The frequency and clinical significance of intra-amniotic infection and/or inflammation in women with placenta previa and vaginal bleeding: an unexpected observation. J Perinat Med. 2010;38:275–9.10.1515/jpm.2010.001Search in Google Scholar PubMed PubMed Central
[212] Cruciani L, Romero R, Vaisbuch E, Kusanovic JP, Chaiworapongsa T, Mazaki-Tovi S, et al. Pentraxin 3 in amniotic fluid: a novel association with intra-amniotic infection and inflammation. J Perinat Med. 2010;38:161–71.10.1515/jpm.2009.141Search in Google Scholar PubMed PubMed Central
[213] Gervasi MT, Romero R, Bracalente G, Erez O, Dong Z, Hassan SS, et al. Midtrimester amniotic fluid concentrations of interleukin-6 and interferon-gamma-inducible protein-10: evidence for heterogeneity of intra-amniotic inflammation and associations with spontaneous early (<32 weeks) and late (>32 weeks) preterm delivery. J Perinat Med. 2012;40:329–43.10.1515/jpm-2012-0034Search in Google Scholar
[214] Gibbs RS, Dinsmoor MJ, Newton ER, Ramamurthy RS. A randomized trial of intrapartum versus immediate postpartum treatment of women with intra-amniotic infection. Obstet Gynecol. 1988;72:823–8.10.1097/00006250-198812000-00001Search in Google Scholar
[215] Chaiworapongsa T, Romero R, Kim JC, Kim YM, Blackwell SC, Yoon BH, et al. Evidence for fetal involvement in the pathologic process of clinical chorioamnionitis. Am J Obstet Gynecol. 2002;186:1178–82.10.1067/mob.2002.124042Search in Google Scholar
[216] Madsen-Bouterse SA, Romero R, Tarca AL, Kusanovic JP, Espinoza J, Kim CJ, et al. The transcriptome of the fetal inflammatory response syndrome. American journal of reproductive immunology. 2010;63:73–92.10.1111/j.1600-0897.2009.00791.xSearch in Google Scholar
[217] Vaisbuch E, Romero R, Gomez R, Kusanovic JP, Mazaki-Tovi S, Chaiworapongsa T, et al. An elevated fetal interleukin-6 concentration can be observed in fetuses with anemia due to Rh alloimmunization: implications for the understanding of the fetal inflammatory response syndrome. J Matern Fetal Neonatal Med. 2011;24:391–6.10.3109/14767058.2010.507294Search in Google Scholar
[218] Park JS, Romero R, Yoon BH, Moon JB, Oh SY, Han SY, et al. The relationship between amniotic fluid matrix metalloproteinase-8 and funisitis. Am J Obstet Gynecol. 2001;185:1156–61.10.1067/mob.2001.117679Search in Google Scholar
[219] Yoon BH, Romero R, Shim JY, Shim SS, Kim CJ, Jun JK. C-reactive protein in umbilical cord blood: a simple and widely available clinical method to assess the risk of amniotic fluid infection and funisitis. J Matern Fetal Neonatal Med. 2003;14:85–90.10.1080/jmf.14.2.85.90Search in Google Scholar
[220] Park CW, Lee SM, Park JS, Jun JK, Romero R, Yoon BH. The antenatal identification of funisitis with a rapid MMP-8 bedside test. J Perinat Med. 2008;36:497–502.10.1515/JPM.2008.079Search in Google Scholar
[221] Romero R, Ceska M, Avila C, Mazor M, Behnke E, Lindley I. Neutrophil attractant/activating peptide-1/interleukin-8 in term and preterm parturition. Am J Obstet Gynecol. 1991;165(4 Pt 1):813–20.10.1016/0002-9378(91)90422-NSearch in Google Scholar
[222] Cherouny PH, Pankuch GA, Romero R, Botti JJ, Kuhn DC, Demers LM, et al. Neutrophil attractant/activating peptide-1/interleukin-8: association with histologic chorioamnionitis, preterm delivery, and bioactive amniotic fluid leukoattractants. Am J Obstet Gynecol. 1993;169:1299–303.10.1016/0002-9378(93)90297-VSearch in Google Scholar
[223] Hsu CD, Meaddough E, Aversa K, Hong SF, Lu LC, Jones DC, et al. Elevated amniotic fluid levels of leukemia inhibitory factor, interleukin 6, and interleukin 8 in intra-amniotic infection. Am J Obstet Gynecol. 1998;179:1267–70.10.1016/S0002-9378(98)70144-9Search in Google Scholar
[224] Ghezzi F, Gomez R, Romero R, Yoon BH, Edwin SS, David C, et al. Elevated interleukin-8 concentrations in amniotic fluid of mothers whose neonates subsequently develop bronchopulmonary dysplasia. Eur J Obstet Gynecol Reprod Biol. 1998;78:5–10.10.1016/S0301-2115(97)00236-4Search in Google Scholar
[225] Figueroa R, Garry D, Elimian A, Patel K, Sehgal PB, Tejani N. Evaluation of amniotic fluid cytokines in preterm labor and intact membranes. J Matern Fetal Neonatal Med. 2005;18:241–7.10.1080/13506120500223241Search in Google Scholar
[226] Yoneda S, Sakai M, Sasaki Y, Shiozaki A, Hidaka T, Saito S. Interleukin-8 and glucose in amniotic fluid, fetal fibronectin in vaginal secretions and preterm labor index based on clinical variables are optimal predictive markers for preterm delivery in patients with intact membranes. J Obstet Gynaecol Res. 2007;33:38–44.10.1111/j.1447-0756.2007.00474.xSearch in Google Scholar
[227] Jacobsson B, Mattsby-Baltzer I, Hagberg H. Interleukin-6 and interleukin-8 in cervical and amniotic fluid: relationship to microbial invasion of the chorioamniotic membranes. BJOG: Int J Obstet Gynaec. 2005;112:719–24.10.1111/j.1471-0528.2005.00536.xSearch in Google Scholar
[228] Kacerovsky M, Drahosova M, Hornychova H, Pliskova L, Bolehovska R, Forstl M, et al. Value of amniotic fluid interleukin-8 for the prediction of histological chorioamnionitis in preterm premature rupture of membranes. Neuro Endocrinol Lett. 2009;30:733–8.Search in Google Scholar
[229] Keelan JA, Yang J, Romero RJ, Chaiworapongsa T, Marvin KW, Sato TA, et al. Epithelial cell-derived neutrophil-activating peptide-78 is present in fetal membranes and amniotic fluid at increased concentrations with intra-amniotic infection and preterm delivery. Biol Reprod. 2004;70:253–9.10.1095/biolreprod.103.016204Search in Google Scholar
[230] Nhan-Chang CL, Romero R, Kusanovic JP, Gotsch F, Edwin SS, Erez O, et al. A role for CXCL13 (BCA-1) in pregnancy and intra-amniotic infection/inflammation. J Matern Fetal Neonatal Med. 2008;21:763–75.10.1080/14767050802244946Search in Google Scholar
[231] Romero R, Quintero R, Emamian M, Wan M, Grzyboski C, Hobbins JC, et al. Arachidonate lipoxygenase metabolites in amniotic fluid of women with intra-amniotic infection and preterm labor. Am J Obstet Gynecol. 1987;157:1454–60.10.1016/S0002-9378(87)80243-0Search in Google Scholar
[232] Hamill N, Romero R, Gotsch F, Kusanovic JP, Edwin S, Erez O, et al. Exodus-1 (CCL20): evidence for the participation of this chemokine in spontaneous labor at term, preterm labor, and intrauterine infection. J Perinat Med. 2008;36:217–27.10.1515/JPM.2008.034Search in Google Scholar PubMed PubMed Central
[233] Mittal P, Romero R, Kusanovic JP, Edwin SS, Gotsch F, Mazaki-Tovi S, et al. CXCL6 (granulocyte chemotactic protein-2): a novel chemokine involved in the innate immune response of the amniotic cavity. Am J Reprod Immunol. 2008;60:246–57.10.1111/j.1600-0897.2008.00620.xSearch in Google Scholar PubMed PubMed Central
[234] Romero R, Salafia CM, Athanassiadis AP, Hanaoka S, Mazor M, Sepulveda W, et al. The relationship between acute inflammatory lesions of the preterm placenta and amniotic fluid microbiology. Am J Obstet Gynecol. 1992;166:1382–8.10.1016/0002-9378(92)91609-ESearch in Google Scholar
[235] Park HS, Romero R, Lee SM, Park CW, Jun JK, Yoon BH. Histologic chorioamnionitis is more common after spontaneous labor than after induced labor at term. Placenta. 2010;31:792–5.10.1016/j.placenta.2010.06.013Search in Google Scholar
[236] Lee SM, Lee KA, Kim SM, Park CW, Yoon BH. The risk of intra-amniotic infection, inflammation and histologic chorioamnionitis in term pregnant women with intact membranes and labor. Placenta. 2011;32:516–21.10.1016/j.placenta.2011.03.012Search in Google Scholar
[237] Mi Lee S, Romero R, Lee KA, Jin Yang H, Joon Oh K, Park CW, et al. The frequency and risk factors of funisitis and histologic chorioamnionitis in pregnant women at term who delivered after the spontaneous onset of labor. J Matern Fetal Neonatal Med. 2011;24:37–42.10.3109/14767058.2010.482622Search in Google Scholar
[238] Hillier SL, Witkin SS, Krohn MA, Watts DH, Kiviat NB, Eschenbach DA. The relationship of amniotic fluid cytokines and preterm delivery, amniotic fluid infection, histologic chorioamnionitis, and chorioamnion infection. Obstet Gynecol. 1993;81:941–8.Search in Google Scholar
[239] Kim CJ, Yoon BH, Park SS, Kim MH, Chi JG. Acute funisitis of preterm but not term placentas is associated with severe fetal inflammatory response. Hum Pathol. 2001;32:623–9.10.1053/hupa.2001.24992Search in Google Scholar
[240] Rogers BB, Alexander JM, Head J, McIntire D, Leveno KJ. Umbilical vein interleukin-6 levels correlate with the severity of placental inflammation and gestational age. Hum Pathol. 2002;33:335–40.10.1053/hupa.2002.32214Search in Google Scholar
[241] Lee J, Oh KJ, Park CW, Park JS, Jun JK, Yoon BH. The presence of funisitis is associated with a decreased risk for the development of neonatal respiratory distress syndrome. Placenta. 2011;32:235–40.10.1016/j.placenta.2010.11.006Search in Google Scholar
[242] Gugino LJ, Buerger PT, Wactawski-Wende J, Fisher J. Chorioamnionitis: the association between clinical and histological diagnosis. Primary Care Update Ob/Gyns. 1998;5:148.10.1016/S1068-607X(98)00026-2Search in Google Scholar
[243] Kim CJ, Yoon BH, Park SH, Chi JG. Histotopographic distribution of placental inflammation: analysis of 22 cases. J Korean Med Sci. 1998;13:519–24.10.3346/jkms.1998.13.5.519Search in Google Scholar PubMed PubMed Central
[244] Oh KJ, Park KH, Kim SN, Jeong EH, Lee SY, Yoon HY. Predictive value of intra-amniotic and serum markers for inflammatory lesions of preterm placenta. Placenta. 2011;32:732–6.10.1016/j.placenta.2011.07.080Search in Google Scholar PubMed
[245] Erdemir G, Kultursay N, Calkavur S, Zekioglu O, Koroglu OA, Cakmak B, et al. Histological chorioamnionitis: effects on premature delivery and neonatal prognosis. Pediatr Neonatol. 2013;54:267–74.10.1016/j.pedneo.2013.03.012Search in Google Scholar
[246] Park CW, Yoon BH, Kim SM, Park JS, Jun JK. The frequency and clinical significance of intra-amniotic inflammation defined as an elevated amniotic fluid matrix metalloproteinase-8 in patients with preterm labor and low amniotic fluid white blood cell counts. Obstet Gynecol Sci. 2013;56:167–75.10.5468/ogs.2013.56.3.167Search in Google Scholar
[247] Keenan WJ, Steichen JJ, Mahmood K, Altshuler G. Placental pathology compared with clinical outcome: a retrospective blind review. Am J Dis Child. 1977;131:1224–7.10.1001/archpedi.1977.02120240042009Search in Google Scholar
[248] Russell P. Inflammatory lesions of the human placenta, I: clinical significance of acute chorioamnionitis. Am J Diagn Gynecol Obstet. 1979;1:127–37.Search in Google Scholar
[249] Arias F, Victoria A, Cho K, Kraus F. Placental histology and clinical characteristics of patients with preterm premature rupture of membranes. Obstet Gynecol. 1997;89:265–71.10.1016/S0029-7844(96)00451-6Search in Google Scholar
[250] Ogunyemi D, Murillo M, Jackson U, Hunter N, Alperson B. The relationship between placental histopathology findings and perinatal outcome in preterm infants. J Matern Fetal Neonatal Med. 2003;13:102–9.10.1080/jmf.13.2.102.109Search in Google Scholar PubMed
[251] Dempsey E, Chen MF, Kokottis T, Vallerand D, Usher R. Outcome of neonates less than 30 weeks gestation with histologic chorioamnionitis. Am J Perinatol. 2005;22:155–9.10.1055/s-2005-865020Search in Google Scholar PubMed
[252] Andrews WW, Goldenberg RL, Faye-Petersen O, Cliver S, Goepfert AR, Hauth JC. The Alabama Preterm Birth study: polymorphonuclear and mononuclear cell placental infiltrations, other markers of inflammation, and outcomes in 23- to 32-week preterm newborn infants. Am J Obstet Gynecol. 2006;195:803–8.10.1016/j.ajog.2006.06.083Search in Google Scholar PubMed
[253] Veleminsky M, Jr., Pradna J, Veleminsky M, Sr., Tosner J. Relationship of amniotic-type placenta inflammation to pPROM, PROM and risk of early onset neonatal sepsis. Neuro Endocrinol Lett. 2008;29:447–50.Search in Google Scholar
[254] Moscuzza F, Belcari F, Nardini V, Bartoli A, Domenici C, Cuttano A, et al. Correlation between placental histopathology and fetal/neonatal outcome: chorioamnionitis and funisitis are associated to intraventricular haemorrage and retinopathy of prematurity in preterm newborns. Gynecol Endocrinol: Official J International Society of Gynecological Endocrinology. 2011;27:319v23.10.3109/09513590.2010.487619Search in Google Scholar PubMed
[255] Tsiartas P, Kacerovsky M, Musilova I, Hornychova H, Cobo T, Savman K, et al. The association between histological chorioamnionitis, funisitis and neonatal outcome in women with preterm prelabor rupture of membranes. J Matern Fetal Neonatal Med. 2013;26:1332–6.10.3109/14767058.2013.784741Search in Google Scholar PubMed
[256] Arayici S, Kadioglu Simsek G, Oncel MY, Eras Z, Canpolat FE, Oguz SS, et al. The effect of histological chorioamnionitis on the short-term outcome of preterm infants </=32 weeks: a single-center study. J Matern Fetal Neonatal Med. 2014;27:1129–33.10.3109/14767058.2013.850668Search in Google Scholar PubMed
[257] St Geme JW, Jr., Murray DL, Carter J, Hobel CJ, Leake RD, Anthony BF, et al. Perinatal bacterial infection after prolonged rupture of amniotic membranes: an analysis of risk and management. J Pediatr. 1984;104:608–13.10.1016/S0022-3476(84)80562-4Search in Google Scholar
[258] Hoang D, Charlagorla P, Salafia C, VanHorn S, Dygulska B, Narula P, et al. Histologic chorioamnionitis as a consideration in the management of newborns of febrile mothers. J Matern Fetal Neonatal Med. 2013;26:828–32.10.3109/14767058.2012.751368Search in Google Scholar
[259] Cuna A, Hakima L, Tseng YA, Fornier B, Islam S, Quintos-Alagheband ML, et al. Clinical dilemma of positive histologic chorioamnionitis in term newborn. Front Pediatr. 2014;2:27.10.3389/fped.2014.00027Search in Google Scholar
[260] Overbach AM, Daniel SJ, Cassady G. The value of umbilical cord histology in the management of potential perinatal infection. J Pediatr. 1970;76:22–31.10.1016/S0022-3476(70)80125-1Search in Google Scholar
[261] Cassell GH, Davis RO, Waites KB, Brown MB, Marriott PA, Stagno S, et al. Isolation of Mycoplasma hominis and Ureaplasma urealyticum from amniotic fluid at 16–20 weeks of gestation: potential effect on outcome of pregnancy. Sex Transm Dis. 1983;10(Suppl 4):294–302.Search in Google Scholar
[262] Gray DJ, Robinson HB, Malone J, Thomson RB, Jr. Adverse outcome in pregnancy following amniotic fluid isolation of Ureaplasma urealyticum. Prenat Diagn. 1992;12:111–7.10.1002/pd.1970120206Search in Google Scholar PubMed
[263] Horowitz S, Mazor M, Romero R, Horowitz J, Glezerman M. Infection of the amniotic cavity with Ureaplasma urealyticum in the midtrimester of pregnancy. J Reprod Med. 1995;40:375–9.Search in Google Scholar
[264] McCracken GH, Jr., Shinefield HR. Changes in the pattern of neonatal septicemia and meningitis. Am J Dis Child. 1966;112:33–9.10.1001/archpedi.1966.02090100069006Search in Google Scholar PubMed
[265] Seo K, McGregor JA, French JI. Preterm birth is associated with increased risk of maternal and neonatal infection. Obstet Gynecol. 1992;79:75–80.Search in Google Scholar
[266] Stoll BJ, Hansen NI, Adams-Chapman I, Fanaroff AA, Hintz SR, Vohr B, et al. Neurodevelopmental and growth impairment among extremely low-birth-weight infants with neonatal infection. J Am Med Assoc. 2004;292:2357–65.10.1001/jama.292.19.2357Search in Google Scholar PubMed
[267] Roman J, Fernandez F, Velasco F, Rojas R, Roldan MR, Torres A. Serum TNF levels in neonatal sepsis and septic shock. Acta Paediatrica. 1993;82:352–4.10.1111/j.1651-2227.1993.tb12695.xSearch in Google Scholar PubMed
[268] Atici A, Satar M, Cetiner S, Yaman A. Serum tumor necrosis factor-alpha in neonatal sepsis. Am J Perinatol. 1997;14:401–4.10.1055/s-2007-994168Search in Google Scholar PubMed
[269] Stout MJ, Conlon B, Landeau M, Lee I, Bower C, Zhao Q, et al. Identification of intracellular bacteria in the basal plate of the human placenta in term and preterm gestations. Am J Obstet Gynecol. 2013;208:226 e1–7.10.1016/j.ajog.2013.01.018Search in Google Scholar PubMed PubMed Central
[270] Kolaczkowska E, Kubes P. Neutrophil recruitment and function in health and inflammation. Nat Rev Immunol. 2013;13:159–75.10.1038/nri3399Search in Google Scholar PubMed
The authors stated that there are no conflicts of interest regarding the publication of this article.
©2016 by De Gruyter
Articles in the same Issue
- Frontmatter
- Editorial
- Clinical chorioamnionitis – an ongoing obstetrical conundrum
- Original articles
- Clinical chorioamnionitis at term II: the intra-amniotic inflammatory response
- Clinical chorioamnionitis at term III: how well do clinical criteria perform in the identification of proven intra-amniotic infection?
- Clinical chorioamnionitis at term VI: acute chorioamnionitis and funisitis according to the presence or absence of microorganisms and inflammation in the amniotic cavity
- Clinical chorioamnionitis at term V: umbilical cord plasma cytokine profile in the context of a systemic maternal inflammatory response
- Clinical chorioamnionitis at term IV: the maternal plasma cytokine profile
- Screening of lysyl oxidase (LOX) and lysyl oxidase like (LOXL) enzyme expression and activity in preterm prelabor rupture of fetal membranes
- Letter to the Editor
- GPR120 local regulation might explain the contradictory pro/anti-inflammatory effects of ω-3 PUFA observed in gestational tissue
- Letter Reply
- Reply to: GPR120 local regulation might explain the contradictory pro/anti-inflammatory effects of ω-3 PUFA observed in gestational tissues
- Congress Calendar
- Congress Calendar
Articles in the same Issue
- Frontmatter
- Editorial
- Clinical chorioamnionitis – an ongoing obstetrical conundrum
- Original articles
- Clinical chorioamnionitis at term II: the intra-amniotic inflammatory response
- Clinical chorioamnionitis at term III: how well do clinical criteria perform in the identification of proven intra-amniotic infection?
- Clinical chorioamnionitis at term VI: acute chorioamnionitis and funisitis according to the presence or absence of microorganisms and inflammation in the amniotic cavity
- Clinical chorioamnionitis at term V: umbilical cord plasma cytokine profile in the context of a systemic maternal inflammatory response
- Clinical chorioamnionitis at term IV: the maternal plasma cytokine profile
- Screening of lysyl oxidase (LOX) and lysyl oxidase like (LOXL) enzyme expression and activity in preterm prelabor rupture of fetal membranes
- Letter to the Editor
- GPR120 local regulation might explain the contradictory pro/anti-inflammatory effects of ω-3 PUFA observed in gestational tissue
- Letter Reply
- Reply to: GPR120 local regulation might explain the contradictory pro/anti-inflammatory effects of ω-3 PUFA observed in gestational tissues
- Congress Calendar
- Congress Calendar
