Maternal and Neonatal Infectious Outcomes Compared According to Rupture of Membrane Duration and Antibiotic Administration A Retrospective Study

Background: Prolonged rupture of membranes (ROM) is associated with peripartum infections; the optimal timing to initiate prophylactic antibiotic treatment is inconclusive. We compared maternal and neonatal infectious morbidity and bacterial distribution in chorioamniotic-membrane cultures according to a ROM-to-delivery interval of 12–18 versus ≥18 hours. Methods: This retrospective cohort study was conducted in a single tertiary university-affiliated hospital from January 2020 to January 2023. Labor was induced in term singleton pregnant women with ROM ≥12 hours who did not deliver spontaneously within 12–24 hours. Prophylactic ampicillin was administered based on risk factors. Outcomes were compared between ROM 12–18 hours (n = 683) and >18 hours (n = 1039); the latter uniformly received intrapartum antibiotics. The primary maternal outcome was clinical chorioamnionitis. The secondary outcomes included intrapartum fever, cesarean delivery, puerperal endometritis and hospitalization length. Neonatal outcomes included early-onset sepsis, 5-minute Apgar score <7, length of stay, respiratory distress and ventilation support. Results: The clinical chorioamnionitis rate was comparable between the ROM 12- to 18- and the ≥18-hour groups. However, intrapartum fever occurred more frequently in the former (15.5% vs. 11.6%, P = 0.024), and postoperative infections were significantly higher (11.7% vs. 4.5%, P = 0.020). Cesarean deliveries were more common in ROM ≥18 versus 12–18 hours (21.3% vs. 16.3%, P = 0.028). Neonatal outcomes were similar between the groups. The bacterial distributions among chorioamniotic-membrane cultures were similar, the most common isolated pathogens were Enterobacteriaceae. Conclusions: Although the risk of chorioamnionitis was similar, the incidence of intrapartum fever and postoperative infections were higher in ROM 12–18 versus ≥18 hours. Initiating antibiotic prophylactic treatment at 12 hours post-prelabor ROM may be beneficial.