The Relationship between Group B Streptococcus Infection in the Vagina with C-Reactive Protein and Procalcitonin Levels in Pregnant Women with Preterm Premature Rupture of Membranes

Background: Preterm premature rupture of membranes (PPROM) is a significant obstetric complication, contributing to increased maternal and neonatal morbidity and mortality. Group B Streptococcus (GBS) infection is a key factor associated with PPROM, inducing inflammation and weakening of the fetal membranes. C-reactive protein (CRP) and procalcitonin are biomarkers of inflammation that may aid in early detection of GBS infection in pregnant women with PPROM. Methods: A cross-sectional study was conducted involving 64 pregnant women with PPROM treated at Prof. Dr. I.G.N.G. Ngoerah General Hospital, Denpasar, from March 2023 to May 2024. Vaginal and rectal swabs were cultured to identify GBS. Serum CRP and procalcitonin levels were measured. Pearson correlation and chi-square tests were used to analyze the relationship between GBS infection and these biomarkers. Results: The prevalence of GBS infection among participants was 50%. CRP levels were significantly higher in GBS-positive cases (mean 7.88 mg/L) compared to GBS-negative cases (mean 3.43 mg/L; p = 0.038), with a strong positive correlation (r = 0.824). Procalcitonin levels were also elevated in GBS-positive cases (mean 0.066 ng/mL) vs. GBS-negative cases (mean 0.031 ng/mL; p = 0.044), showing a moderate positive correlation (r = 0.567). Sensitivity and specificity were 80% and 76.5% for CRP and 75% and 69.5% for procalcitonin, respectively. CRP demonstrated a prevalence ratio (PR) of 4.16, indicating a stronger association with GBS infection compared to procalcitonin (PR 3.08). Conclusion: Both CRP and procalcitonin are valuable markers for diagnosing GBS infection in pregnant women with PPROM. CRP exhibits stronger diagnostic performance and is recommended as the primary biomarker. Procalcitonin serves as a complementary tool, enhancing the diagnostic process. These findings underscore the importance of integrating these markers into clinical practice to improve maternal and neonatal outcomes.