Research
Imaging
Identification of intracellular bacteria in the basal plate of the human placenta in term and preterm gestations

https://doi.org/10.1016/j.ajog.2013.01.018Get rights and content

Objective

Bacteria have been identified in different regions of the placenta. Here, we tested the hypothesis that the maternal basal plate of the placenta harbors microbes that may be associated with adverse pregnancy outcomes.

Study Design

We performed a cross-sectional study of pregnancies from a single tertiary care hospital. Maternal medical and obstetric characteristics were obtained and pregnancies followed up prospectively for outcomes and placental collection. After delivery, systematic random sampling of the placental basal plate was performed. Paraffin sections of basal plates were stained with 4 histologic stains and scored for morphological evidence of bacteria.

Results

Of 195 total patients in the study, Gram-positive and -negative intracellular bacteria of diverse morphologies were documented in the basal plates of 27% of all placentas. Of the patients, 35% delivered preterm. No difference was noted between placental basal plates from preterm or term gestations. Intracellular bacteria were found in the placental basal plates of 54% spontaneous preterm deliveries <28 weeks, and in 26% of term spontaneous deliveries (P = .02). Intracellular bacteria were also documented in placentas without clinical or pathologic chorioamnionitis.

Conclusion

A total of 27% of placentas demonstrated intracellular bacteria in the placental basal plate using morphological techniques. Thus, the maternal basal plate is a possible source of intrauterine colonization and placental pathological examination could include examination for bacteria in this important maternal–fetal interface.

Section snippets

Study design

This is a cross-sectional study of women from a single tertiary care hospital. The study was approved by the institutional review board of Washington University School of Medicine in St. Louis, MO. Women were enrolled during their antenatal course and followed up until delivery. Clinical data and placental specimens were collected through an institutional core resource, the Women's and Infant's Health Specimen Consortium. Gestational age was assigned by the best data available from the last

Results

Of 195 pregnancies evaluated in this study, 27% had evidence of intracellular bacteria in the basal plate of the placenta. Demographic characteristics of the patients who participated are demonstrated in Table 1. The multiple histologic stains used in this study assured us that we could determine both morphology and location of bacteria within cells in the basal plate if they were present, as posed in our hypothesis. We identified individual bacteria and biofilm-like clusters of bacteria in the

Principal findings of the study

This study demonstrates the first morphological documentation of intracellular organisms in the decidual basal plate of human placentas. Microbial biofilms, defined as microbial communities encapsulated within polysaccharide matrices,19 have been implicated in >80% of human infections such as periodontitis, urethritis, endocarditis, cystitis, and device-associated infections. Romero et al3 and DiGiulio et al20 demonstrated that there were biofilms in amniotic fluid. Here, we show that 27% of

Acknowledgments

We thank Fredrick Kraus, MD, and Phyllis Huettner, MD, for their expertise and assistance with histopathology interpretation.

References (42)

  • W.W. Andrews et al.

    Endometrial microbial colonization and plasma cell endometritis after spontaneous or indicated preterm versus term delivery

    Am J Obstet Gynecol

    (2005)
  • A.B. Onderdonk et al.

    Colonization of second-trimester placenta parenchyma

    Am J Obstet Gynecol

    (2008)
  • K.K. Jefferson

    The bacterial etiology of preterm birth

    Adv Appl Microbiol

    (2012)
  • L.A. Schieve et al.

    Urinary tract infection during pregnancy: its association with maternal morbidity and perinatal outcome

    Am J Public Health

    (1994)
  • J.C. Carey et al.

    Metronidazole to prevent preterm delivery in pregnant women with asymptomatic bacterial vaginosis: National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units

    N Engl J Med

    (2000)
  • M.A. Klebanoff et al.

    Failure of metronidazole to prevent preterm delivery among pregnant women with asymptomatic Trichomonas vaginalis infection

    N Engl J Med

    (2001)
  • H.M. McDonald et al.

    Antibiotics for treating bacterial vaginosis in pregnancy

    Cochrane Database Syst Rev

    (2007)
  • I.U. Mysorekar et al.

    Mechanisms of uropathogenic Escherichia coli persistence and eradication from the urinary tract

    Proc Natl Acad Sci U S A

    (2006)
  • T.F. McElrath et al.

    Pregnancy disorders that lead to delivery before the 28th week of gestation: an epidemiologic approach to classification

    Am J Epidemiol

    (2008)
  • A. Leviton et al.

    Microbiologic and histologic characteristics of the extremely preterm infant's placenta predict white matter damage and later cerebral palsy: the ELGAN study

    Pediatr Res

    (2010)
  • R.N. Fichorova et al.

    Maternal microbe-specific modulation of inflammatory response in extremely low-gestational-age newborns

    MBio

    (2011)
  • Cited by (0)

    M.J.S. is supported by Eunice Kennedy Shriver National Institute of Child Health and Human Development T32 grant number 5 T32 HD055172-02 and Washington University Clinical and Translational Science Award grant number UL1 RR024992. I.U.M. is supported by a Preterm Birth Research Grant from the Burroughs Wellcome Fund.

    The authors report no conflict of interest.

    The Women's and Infant's Health Specimen Consortium was funded by grants from the Washington University Clinical and Translational Science (National Institutes of Health UL1 RR024992) and the Children's Discovery Institute of St. Louis Children's Hospital.

    Cite this article as: Stout MJ, Conlon B, Landeau M, 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.

    View full text