Two Prophylactic Antibiotic Protocols Compared for the Treatment of Preterm Pre-labour Rupture of Membranes

Objectives

Antibiotic prophylaxis in preterm pre-labour rupture of membranes (PPROM) is associated with a reduced rate of clinical chorioamnionitis. In recent randomized controlled trials, cefuroxime combined with a macrolide was more effective than traditional ampicillin-based regimens in prolonging latency and reducing gram-negative neonatal infections. Accordingly, our institution revised its PPROM prophylactic antibiotic protocol from ampicillin and roxithromycin to cefuroxime and azithromycin. We compared the infectious morbidity associated with these 2 regimens to assess their clinical effectiveness in routine practice.

Methods

This retrospective study included 170 women with PPROM at <37⁰ weeks gestation, managed expectantly and treated with antibiotic prophylactic protocols: 83 received ampicillin and roxithromycin from February 2022 to March 2023, and 87 received cefuroxime and azithromycin from April 2023 to May 2024. We conducted a multivariate regression analysis to predict clinical chorioamnionitis rates, controlled for PPROM week, group B Streptococcus colonization, antibiotic regimen, and latency.

Results

Gestational age at PPROM, parity, group B Streptococcus status, and the latency period were comparable between the groups. In the ampicillin and roxithromycin group, compared with the cefuroxime and azithromycin group, intrapartum fever and clinical chorioamnionitis rates were higher (9.6% vs. 1.1%, P = 0.013 and 8.4% vs. 1.1%, P = 0.046, respectively). Compared with the later regimen, the earlier regimen was associated with higher rates of cesarean delivery, maternal postpartum infections, and antibiotic treatment (33.7% vs. 19.5%, P = 0.036; 4.8% vs. 0%, P = 0.038; and 9.6% vs. 2.3%, P = 0.042; respectively). Positive chorioamniotic membrane cultures and ampicillin-resistant Enterobacteriaceae species were more prevalent in the ampicillin and roxithromycin group (67.8% vs. 50.0%, P < 0.001, and 23% vs. 10%, P = 0.027, respectively).

Conclusions

Cefuroxime plus azithromycin as prophylaxis for PPROM at <37⁰ weeks showed fewer maternal peripartum infectious outcomes than ampicillin plus roxithromycin; this was supported by bacteriologic findings.