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.