Maternal and neonatal outcomes and histological chorioamnionitis in preterm premature rupture of membranes complicated by group B streptococcus colonization: a retrospective analysis

Histological chorioamnionitis (HCA) is frequently identified in placental examinations following preterm premature rupture of membranes (PPROM). Colonization of the genital tract by Group B Streptococcus (GBS) represents a major risk factor for serious neonatal infections. This study evaluated the influence of GBS on both maternal and neonatal outcomes in pregnancies complicated by PPROM before 34 weeks’ gestation managed expectantly. We conducted a retrospective analysis of clinical records from pregnant women experiencing spontaneous PPROM between 23 + 0 and 33 + 6 weeks’ gestation, who underwent vaginal microbiota screening at Hangzhou Maternal and Child Health Hospital between January 2019 and December 2023. Data on sociodemographic characteristics, vaginal microbiota, pregnancy outcomes, and neonatal Apgar scores were collected for patients with PPROM. Among 308 patients meeting the inclusion criteria, 24 (7.79%) tested positive for GBS. The GBS-positive group demonstrated significantly higher rates of HCA, neonatal respiratory distress syndrome (RDS), and neonatal intraventricular hemorrhage (IVH) compared to the GBS-negative group (p < 0.05). No statistically significant differences were observed between the groups regarding clinical chorioamnionitis, puerperal infection, postpartum hemorrhage, fetal distress, Apgar scores, neonatal sepsis, or necrotizing enterocolitis. In patients with PPROM before 34 weeks’ gestation, colonization with GBS may be associated with poorer neonatal outcomes and an increased incidence of maternal HCA.