Evaluation of serum level of C-reactive protein (CRP) and its correlation with fetal ultrasound parameters in the prediction of threatened miscarriage in the first trimester

Background: Pregnancy loss occurring before 20 weeks gestation is referred to as miscarriage. Various clinical presentations of miscarriage include threatened, inevitable, incomplete, complete, septic, and missed miscarriage. Early-stage threatened miscarriage may manifest with symptoms such as abdominal discomfort and vaginal bleeding. Threatened miscarriage is clinically defined as the manifestation of positive fetal heart sounds in pregnancies occurring before the 20th week of gestation, concomitant with vaginal bleeding and a closed cervix. Objectives: The primary aim of this study was to evaluate the association between serum C-reactive protein (CRP) levels and fetal ultrasound findings in the prediction of threatened miscarriage during the first trimester of pregnancy. Methods: In this prospective case-control study, a total of 100 pregnant women at 7–13 weeks of gestation were enrolled. All participants initially presented with a singleton embryo displaying cardiac activity on ultrasound. The study cohort was divided into two groups: Group 1 consisted of 50 women with uncomplicated pregnancies, while Group 2 comprised 50 women experiencing symptoms indicative of threatened miscarriage. Results: Notably, within Group 2, patients who eventually experienced miscarriage exhibited significantly elevated serum high-sensitivity CRP levels in comparison to those who maintained their pregnancies. Conclusions: Threatened miscarriage cases demonstrated a substantial increase in serum high-sensitivity CRP levels compared to the control group. Furthermore, CRP levels exhibited a correlation with the risk of miscarriage, suggesting their potential utility in conjunction with ultrasound parameters for prognosticating threatened miscarriage during the first trimester.


INTRODUCTION
Miscarriage, defined as the termination of pregnancy before 20 weeks of gestational age, encompasses various types, including threatened, inevitable, incomplete, complete, septic, and missed miscarriage. 1 Among these, threatened miscarriage may manifest in early pregnancy with symptoms such as lower abdominal pain and/or vaginal bleeding.Approximately 25 percent of pregnant women experience some degree of vaginal bleeding during the first two trimesters, and roughly 50 percent of these cases progress to an actual miscarriage. 2ccording to two studies, 16.6% and 13.7% of threatening miscarriage instances experienced spontaneous miscarriages.The first was a case-control study in Turkey, while the second was a retrospective cohort study in a major healthcare facility in Nigeria. 3,4umerous risk factors associated with miscarriage have been identified, including advanced maternal and paternal age, previous pregnancy losses, TORCH infections (Toxoplasmosis, Other (syphilis, varicella-zoster, parvovirus B19), Rubella, Cytomegalovirus (CMV), and Herpes infections), uncontrolled hyperglycemia, obesity, uncontrolled thyroid disease, significant stressors, the use of teratogenic medications, and the presence of a subchorionic hemorrhage.A comprehensive assessment of these risk factors in women presenting with threatened miscarriage can aid in determining prognosis. 5 threatened miscarriage raises the prospect of troubling outcomes, not only for the pregnancy

Participant enrollment
Participants were meticulously screened and categorized into two distinct groups.Group 1 comprised 50 pregnant women with uncomplicated, uneventful pregnancies without significant complications.In contrast, Group 2 encompassed 50 pregnant women presenting with clinical indicators of threatened miscarriage (pregnancies characterized by the presence of positive fetal heart sounds, concurrent vaginal bleeding, and a closed cervix).

Inclusion criteria
Inclusion criteria for study participation encompassed pregnant women aged 20 to 35 years, exhibiting gestational ages between 7-13 weeks, and confirming the presence of a singleton embryo with detectable cardiac activity via ultrasound.Additionally, gestational age determined by the last menstrual period (LMP) was required to align within a 3-day window of ultrasound-derived crown-rump length.

Exclusion criteria
Multiple pregnancies, previous hormonal treatment or progesterone supplementation, pre-existing medical conditions such as diabetes, thyroid disease, or antiphospholipid syndrome, as well as specific gynecological conditions including fibroids/adnexal masses, uterine malformations, obesity, ectopic pregnancy, and molar pregnancy, were grounds for exclusion from the study.

Outcome measures
The primary outcome measure in this study was the determination of serum C-reactive protein (CRP) levels, which were meticulously compared between the cohort presenting with threatened miscarriage and the control group.Serum CRP assessments were performed utilizing blood samples collected at the study's commencement (between 6 -14 weeks gestation) to elucidate potential discrepancies between groups and investigate the correlation of CRP levels with the risk of threatened miscarriage during early pregnancy.

Secondary outcome measures
Secondary outcome measures comprised the assessment of ongoing pregnancy rates at 24 weeks gestation and miscarriage rates before the 20-week gestational mark.These outcome measures were systematically compared between the group of women presenting with threatened miscarriage and the control group characterized by uncomplicated pregnancies.The objective was to discern whether notable disparities in outcomes existed between these two distinct cohorts.
VOL. 2024 / ART. 9 Evaluation of serum level of CRP and its correlation with fetal ultrasound parameters outcome measures underwent a systematic coding process.This coded data was subsequently entered into Microsoft Excel for organized management.

Statistical analysis
The data compiled within Microsoft Excel was subsequently imported into the Statistical Package for the Social Sciences (SPSS version 20.0) for comprehensive analysis.Qualitative data was presented as counts and percentages, whereas quantitative continuous data was expressed as mean values accompanied by their respective standard deviations.Various statistical tests, including Pearson's correlation, Spearman's correlation, and other appropriate tests, were meticulously employed to discern differences between groups and assess statistical significance.For statistical significance, a P value threshold of < 0.05 was considered statistically significant, while a P value of < 0.001 was deemed highly significant.

RESULTS
In this comprehensive study investigating potential predictors of first-trimester miscarriage, our analyses revealed several significant findings across demographic, laboratory, and ultrasound parameters.Independent t-tests showed no statistically significant differences between the patient and control groups for age (p = 0.539) or BMI (p = 0.338).However, ultrasound parameters exhibited substantial variations.Notably, gestational sac diameter (GSD) was significantly

Ethical approval
The study protocol underwent a rigorous ethical review process and received approval from the Institutional Review Board at Al-Azhar University and the Ethical Committee of Al-Azhar Faculty of Medicine.This approval underscores the study's adherence to established ethical standards and principles.

Informed consent
Before participating in the study, all enrolled patients provided written informed consent in a face-to-face interaction.This consent process included a comprehensive explanation of the research objectives and the various study procedures.Ensuring patient autonomy and comprehension was paramount throughout the informed consent process.

Confidentiality and privacy
The study meticulously upheld the principles of patient confidentiality and privacy at every stage of the research endeavor.Stringent measures were in place to safeguard the sensitive personal information of study participants.

Data collection
Information gleaned from medical histories, clinical examinations, laboratory investigations, and   Table 2 shows that progesterone was significantly lower among the patients' group than in the control group.However, there is no significant difference between the groups regarding HCG.* P-value ≤ 0.05 indicates significant, p < 0.001 indicates highly significant, P > 0.05 indicates non-significant.
Table 3 showed that CRP was significantly higher among the patients group than the control group.However, there is no significant difference between the groups regarding PAPP-A.Table 4 shows a significant difference between the groups regarding the ultrasound parameters.
VOL. 2024 / ART. 9 Evaluation of serum level of CRP and its correlation with fetal ultrasound parameters Table 5 shows a significant negative correlation between hs-CRP and FHR among the patients group.Table 6 shows that hs-CRP was significantly higher among miscarriage patients compared to patients who continued pregnancy in the patients' group.However, hs-CRP was higher among miscarriage patients compared to patients who continued pregnancy in the control group but without a statistically significant difference.
different between groups (p < 0.001), emphasizing its potential utility as a predictor.
Specific laboratory parameters were scrutinized for associations with threatened miscarriage.High-sensitivity C-reactive protein (hs-CRP) levels were significantly higher in patients versus controls (p < 0.001), suggesting an association between inflammation and miscarriage risk.Patients who miscarried had markedly higher hs-CRP levels compared to those with ongoing pregnancies (p < 0.001).
Additionally, correlation analysis revealed a significant negative association between hs-CRP and fetal heart rate (FHR) in patients (r = -0.331,p = 0.019), indicating higher hs-CRP related to lower FHR.Receiver operating characteristic curves demonstrated hs-CRP's predictive potential, with a cutoff > 9.3 mg/L showing 65.2% sensitivity and weeks, accompanied by vaginal bleeding and a closed cervix. 9It represents the most common complication of early pregnancy, with an incidence ranging from 14% to 20%. 12 Beyond six weeks gestation, threatened miscarriage carries an approximate 10% risk of progressing to complete miscarriage.Additionally, it has been associated with adverse long-term pregnancy outcomes, including preterm delivery, placental abruption, intrauterine growth restriction, and low birth weight. 13hs-CRP achieved a significant result in predicting miscarriage in the first trimester at cutoff > 9.3 mg/L with a sensitivity of 65.2% and specificity of 89.6% (Table 7 and Figure 1).
In summary, these robust findings provide nuanced insight into relationships between demographic, laboratory, and ultrasound parameters in the context of first-trimester miscarriage prediction.

DISCUSSION
Threatened miscarriage is characterized by the identification of a fetus exhibiting positive cardiac activity within a gestational age of less than 20  Only GSD achieved significance in predicting miscarriage in the first trimester, with a sensitivity of 71.4% and a specificity of 70.9% (Table 8 and Figure 2).
Our study observed no statistically significant differences in age and BMI between the two groups.These findings are consistent with those reported by Jauniaux et al., who conducted a study assessing the role of hs-CRP in predicting and managing miscarriage in women with first-trimester bleeding.Evaluation of serum level of CRP and its correlation with fetal ultrasound parameters neutrophils, monocytes, and lymphocytes in the study group than controls. 15In a related context, Cohen et al. aimed to investigate C-reactive protein (CRP) levels in early pregnancy to detect abnormalities, particularly ectopic pregnancy. 16hey found significantly higher CRP levels in normal pregnancy (Group A) versus abnormal pregnancies (Group B + C and Group B alone), despite no differences in age and BMI between groups.
Our study revealed significantly higher CRP levels in the patient group than in controls, though no significant difference in PAPP-A was observed between groups.These results align with Cohen et al., who reported significant differences between their study groups for CRP levels. 16ikbakht et al. also found a mean serum CRP level of 4.6 ± 2.7 mg/L in patients, along with 89.16% normal fetuses, 10% preterm births, and 5% small-for-gestational-age births. 17 notably higher miscarriage rate was observed in the patient group compared to controls.This finding is consistent with Jauniaux et al., who found no significant difference in miscarriage rates between their study groups. 14ur study established a significant negative correlation between hs-CRP and fetal heart rate in the patient group.Similarly, Bondarenko et al. found that increased hs-CRP levels were associated with fetal disorders, underscoring its role as an inflammation marker in complicated pregnancies. 18e found that hs-CRP was significantly higher in miscarriage patients compared to ongoing pregnancy patients within the patient group but not in controls.These findings agree with Jauniaux et al., who reported significant differences between their study groups for hs-CRP levels. 14Abdelsamie et al. assessed maternal serum hs-CRP and differential leukocyte count (DLC) for diagnosing threatened miscarriage in 100 pregnant women, concluding a significant difference between study groups for hs-CRP levels. 15n our study, only gestational sac diameter (GSD) significantly predicted first-trimester miscarriage, with 71.4% sensitivity and 70.9% specificity.
Tadmor et al. similarly found that the GSD and crown-rump length ratio predicted miscarriage in a prospective cohort, demonstrating a sensitivity of 78.3% and specificity of 97.8%. 19

CONCLUSION
In conclusion, our study provides evidence that pregnant women with threatened miscarriage exhibit significantly elevated serum hs-CRP levels compared to controls, suggesting the potential utility of hs-CRP as a predictive marker in such cases.These findings contribute to the evolving understanding of the multifaceted factors associated with threatened miscarriage and underscore the importance of exploring serologic markers in conjunction with established sonographic parameters for enhanced prognostication.

Figure 1 .
Figure 1.ROC curve for hs-CRP as a predictor for miscarriage in the first trimester.

Figure 2 .
Figure 2. ROC curve for possible US parameters as a predictor for miscarriage in the first trimester.

Table 1 . Demographic distribution between the two groups.
BMI: body mass index; t: Independent T-test.*P-value ≤ 0.05 indicates significant, p < 0.001 indicates highly significant, P > 0.05 indicates non-significant.

Table 3 . Specific laboratory parameters between the two groups.
PAPP-A: pregnancy-associated plasma protein-A; hs-CRP: high-sensitivity C-reactive protein; MW: Mann-Whitney test.

Table 4 . Ultrasound parameters between the two groups.
* P-value ≤ 0.05 indicates significant, p < 0.001 indicates highly significant.