A Study on Group B Streptococcal Colonization in Pregnant Women- A Prospective Observational Study

Introduction: Group B Streptococcus (GBS), a leading cause of neonatal and maternal morbidity, is responsible for early-onset disease (EOD) in neonates and conditions like chorioamnionitis in mothers. GBS colonisation in pregnant women can lead to vertical transmission during labour. Although universal screening has significantly reduced neonatal GBS disease in developed nations, its implementation in developing countries, including India, remains limited. This study aimed to determine the prevalence of GBS colonisation among pregnant women, assess associated maternal and neonatal outcomes, and propose an optimal screening strategy. Materials and Methods: This prospective observational study included 125 pregnant women between 35–37 weeks gestation at Shridevi Institute of Medical Sciences and Research Hospital, Tumkur, Karnataka, over 12 months. Vaginal and rectal swabs were collected, cultured using enrichment broth and sheep blood agar, and analysed using standard microbiological methods. Maternal demographic details, obstetric history, and neonatal outcomes were recorded. Results: GBS colonisation prevalence was 4% (5/125). Colonisation was identified in 40% of vaginal swabs, 40% of anal swabs, and 20% of both. GBS positivity was significantly associated with premature rupture of membranes (p = 0.0017) but not with age, gravidity, or socioeconomic status. No maternal or neonatal morbidity was observed in GBS-positive cases. Neonates of colonised mothers showed no NICU admissions or clinical signs of sepsis. Conclusion: GBS colonisation among pregnant women was low (4%) and significantly associated with PROM. Enhanced detection using dual-site sampling and targeted prophylaxis may mitigate adverse outcomes. More extensive studies are required to inform GBS prevention strategies in India.