Maternal group B Streptococcus colonization: Correlation between IL-6/IL-15 cytokine profiles and infection biomarkers for early risk prediction

Objective: To investigate the risk factors for adverse pregnancy outcomes in women with late-trimester Group B Streptococcus (GBS) colonization and to evaluate the predictive value of serum C-reactive protein (CRP), procalcitonin (PCT), interleukin-6 (IL-6), and interleukin-15 (IL-15) as biomarkers for these outcomes. Methods: This is a prospective cohort study of 160 women (80 GBS-positive and 80 GBS-negative). Clinical data, serum biomarkers (CRP, PCT, IL-6, IL-15), and vaginal secretion samples were collected. Statistical analyses were performed to identify independent risk factors and to assess the diagnostic accuracy of the biomarkers using receiver operating characteristic (ROC) curves. Results: Independent risk factors for adverse pregnancy outcomes in GBS-colonized women include advanced maternal age, gestational diabetes mellitus, a history of miscarriage, and vaginal dysbiosis. The combined measurement of CRP, PCT, IL-6, and IL-15 showed superior predictive value for adverse pregnancy outcomes (AUC = 0.913; 95% CI, 0.85-0.97) compared to individual markers. GBS-positive women exhibited a higher incidence of co-infections and adverse neonatal outcomes, such as pneumonia and asphyxia. Conclusion: TA combination of inflammatory biomarkers can serve as a strong predictor of adverse pregnancy outcomes in women with late-stage GBS colonization. These findings support incorporating biomarker testing into GBS screening protocols to enhance risk assessment and guide clinical management.