2025 Southeastern Residency Conference

Title: Impact of Cefoxitin Monotherapy Versus Traditional Antimicrobial Therapy on Time to Antibiotic Administration in Intra-amniotic Infections: A Retrospective Review
 Authors: Hannah Bischoff, Sarah Withers, Caroline Jozefczyk, Joseph Kohn, R. Jake Crocker, Jasmine Lewis, Carolyn Ellison, Alex Ewing, Pamela Bailey
Objective: Compare the time to antibiotic administration between cefoxitin and the standard of care therapy by measuring the time from when the antibiotic(s) were ordered to the completion of either cefoxitin administration or the completion of both ampicillin and gentamicin administrations.
Self-Assessment Question: Which of the following antimicrobial regimens for empiric coverage of suspected or diagnosed chorioamnionitis demonstrated faster time to administration?
Background: Intra-amniotic infections, like chorioamnionitis, are treated with antimicrobials to reduce maternal and neonatal morbidity and mortality. The American College of Obstetricians and Gynecologists (ACOG) recommends ampicillin and gentamicin as first-line therapy, with clindamycin in cesarean sections for expanded anaerobic coverage. Cefoxitin, a second-generation cephalosporin, offers robust coverage and is a recommended alternative agent. Studies have shown no significant differences in efficacy between cefoxitin and other treatments for obstetric infections. Due to concerns with traditional therapies, such as nephrotoxicity from gentamicin and Clostridioides difficile infections from clindamycin, cefoxitin has emerged as an effective single-agent alternative. A recent study in South Carolina demonstrated that cefoxitin is non-inferior to traditional antimicrobial therapy for treating chorioamnionitis. This study aims to compare the time to antibiotic administration between cefoxitin and traditional antimicrobial therapy of ampicillin and gentamicin, addressing a gap in research on timely treatment for intra-amniotic infections in alignment with ACOG's recommendation to administer antibiotics promptly upon diagnosis.
Methods: This multi-site, retrospective cohort study compared treatment outcomes for chorioamnionitis at Prisma Health sites in South Carolina. The pre-cefoxitin group, treated with ampicillin, gentamicin, with or without clindamycin from June 2022 to May 2023, was compared to the post-cefoxitin group, treated with cefoxitin from June 2023 to May 2024, following an update to institutional guidelines. All pregnant individuals aged 16 and older, with diagnosed or presumed chorioamnionitis, were included. 
Results: A total of 300 patients were included, 150 in both the traditional therapy and cefoxitin group. Baseline characteristics were similar between the traditional therapy and cefoxitin groups, with no statistically significant differences in age (25.4 ± 5.6 vs. 26.3 ± 6.0 years), race distribution, or length of hospital stay (3.3 vs. 3.2 days). Most patients in each group identified as White (45.3% vs. 41.7%), followed by Black (28.7% vs. 20.7%) and Hispanic (18.7% vs. 27.3%). The majority were not Hispanic or Latino (76.7% vs. 68.0%). Vaginal delivery was the most common mode of birth (63.3% vs. 55.3%), with similar rates of cesarean delivery (34.7% vs. 39.3%) and labor induction (62.0% vs. 58.7%). A negative Group B Streptococcus screen was reported in most patients (78.7% vs. 73.3%).
Receipt of antimicrobials within 60–90 minutes of order entry occurred in significantly more patients in the cefoxitin group compared to the traditional therapy group (69.3% vs. 4.7%, p < 0.001). Time to effective therapy was significantly shorter in the cefoxitin group (76.4 ± 93.3 vs. 183.7 ± 228.9 minutes, p < 0.001). Duration of therapy was similar between groups (1.25 ± 0.89 vs. 1.28 ± 1.32 days, p = NS). There were no statistically significant differences in ICU admissions (0 vs. 1 patient), mortality, 30-day infection-related readmission, or need for additional surgical/procedural intervention.
Conclusions: Cefoxitin use for chorioamnionitis significantly improves the time to effective antibiotic treatment, aligning with current guideline recommendations for prompt therapy. The absence of differences in secondary outcomes reinforces the clinical efficacy of cefoxitin, supporting its continued adoption as a first-line agent in the management of chorioamnionitis.