Stephanie Rains, MD, on piperacillin-tazobactam to treat chorioamnionitis

Research presented at the 2026 American College of Obstetricians & Gynecologists (ACOG) Annual Clinical & Scientific Meeting in Washington, DC, indicated that piperacillin-tazobactam may serve as an effective alternative to the traditional ampicillin-gentamicin regimen for the treatment of intrapartum chorioamnionitis. The study, titled "The Effectiveness of Piperacillin-Tazobactam for the Treatment of Chorioamnionitis," evaluated maternal and neonatal outcomes following a multidisciplinary shift in first-line therapy at a metropolitan institution.

The study’s lead author, Stephanie Rains, MD, of Summa Health in Ohio, joined Contemporary OB/GYN at ACOG 2026 to discuss the findings.

Chorioamnionitis complicates 2% to 5% of term pregnancies. While ampicillin-gentamicin has long been the standard of care, rising antibiotic resistance and logistical challenges—such as weight-based dosing and gentamicin stability—prompted Rains’ institution to adopt piperacillin-tazobactam (4.5 g intravenously every 6 hours) in June 2023.

Maternal and neonatal results

The retrospective chart review analyzed 244 deliveries between January 2021 and July 2024, comparing 177 patients treated with piperacillin-tazobactam with 67 patients treated with ampicillin-gentamicin. Primary outcomes, including postpartum infectious morbidity (12% vs 9%, P = .07) and maternal readmission rates (7% vs 9%, P = .65), were similar between the 2 groups.

Secondary maternal outcomes demonstrated no significant difference in fever resolution time, which averaged 4.8 hours for the piperacillin-tazobactam group compared with 4.2 hours for the ampicillin-gentamicin group (P = .12). However, 2 specific maternal outcomes showed statistically significant differences, as follows:

• Transfusion rates: Blood transfusion was more frequent in the piperacillin-tazobactam group (9% vs 1%, P = .04).
• Readmission stay: The length of stay during readmission was longer for those treated with piperacillin-tazobactam (3.2 days vs 2.2 days, P = .047).

Neonatal outcomes, including Apgar scores, respiratory distress syndrome cases, and NICU admissions, showed no significant differences between the regimens.

The investigators concluded, “Piperacillin–tazobactam use for intrapartum chorioamnionitis resulted in comparable neonatal outcomes and generally similar maternal outcomes. Longer readmission stays and higher transfusion rates highlight the importance of antimicrobial stewardship and prospective evaluation.”

Reference

Rains S, Mehl MW, Johnson KN, et al. The effectiveness of piperacillin-tazobactam for the treatment of chorioamnionitis. Presented at: American College of Obstetricians & Gynecologists Annual Clinical & Scientific Meeting; May 1-3, 2026; Washington, DC.