(604) Comparing Two Prophylactic Antibiotic Protocols for Treating Preterm Pre-labor Rupture of Membranes

Objective: Following our randomized trial, we changed the prophylactic antibiotic protocol for preterm pre-labor rupture of membranes (PPROM) in our department from ampicillin-roxithromycin to cefuroxime-azithromycin. We compared the infectious morbidity of these two regimens.

Study Design: This retrospective study included 170 women with PPROM < 37 weeks, managed expectantly with betamethasone and prophylactic antibiotics. According to protocol, chorioamniotic membrane cultures were obtained after delivery. Maternal and neonatal outcomes were compared between 83 women who received ampicillin-roxithromycin (February 2022 - March 2023) and 87 who received cefuroxime-azithromycin (April 2023 - May 2024). A composite maternal postpartum infectious outcome consisted of endometritis, antibiotic treatment and surgical site infection. A composite neonatal adverse outcome consisted of early onset sepsis, admission to the neonatal intensive care unit, antibiotic treatment, sepsis workup and respiratory distress syndrome.

Results: Gestational age at PPROM, parity, group B Streptococcus status and the median latency duration were comparable in the two periods. Among women treated with ampicillin-roxithromycin vs. cefuroxime-azithromycin, a greater proportion had intrapartum fever, clinical chorioamnionitis, cesarean delivery and a postpartum infectious outcome: 9.6% vs 1.1%, p=0.013; 8.4% vs 1.1%, p =0.046; 33.7% vs 19.5%, p=0.036; and 4.8% vs. 0%, p=0.038, respectively (Table). The composite neonatal adverse outcome did not differ between the groups (p=0.874). Following the ampicillin-roxithromycin vs. cefuroxime-azithromycin regimen, prevalences were greater of positive chorioamniotic membrane cultures (50.0% vs. 32%, p< 0.001) (Figure) and of ampicillin-resistant Enterobacteriaceae spp. (23% vs. 10%, p=0.027).

Conclusion: Cefuroxime-azithromycin compared to ampicillin-roxithromycin as a prophylactic for PPROM < 37 weeks showed less maternal peripartum infections, which was supported by the bacteriologic findings.