Poster Session 1
Maryama O. Ismail, MD (she/her/hers)
OBGYN Resident
Mass General Brigham
Boston, MA, United States
Taylor S. Freret, MD, MEd
Beth Israel Deaconess Medical Center
Brookline, MA, United States
Mark A. Clapp, MD, MPH (he/him/his)
Physician Investigator
Massachusetts General Hospital
Boston, MA, United States
Malavika Prabhu, MD (she/her/hers)
Assistant Professor, Division of Maternal Fetal Medicine
Massachusetts General Hospital
Boston, Massachusetts, United States
A 24-hour course of IV antibiotics and indomethacin at the time of exam-indicated cerclage (EIC) is superior to placebo at increasing gestational latency (GL). We sought to determine if a single dose regimen (SDR) of perioperative antibiotic prophylaxis provides similar benefits compared to a multidose regimen (MDR).
Study Design:
This was a retrospective cohort study of patients undergoing an EIC within a single healthcare system from 2017 to 2023. Exclusion criteria included multiple gestation, multiple cerclages in the pregnancy, or no perioperative antibiotics. Surgical case details, antibiotic administration, and delivery outcomes were abstracted from the electronic health record. The exposure was antibiotic duration: SDR (preoperative antibiotics only) vs MDR (preoperative antibiotics with at least one postoperative dose). The primary outcome was time from cerclage placement to delivery (GL) among liveborn infants. Secondary outcomes included gestational age (GA) at delivery. Linear regression analyses controlled for amniocentesis prior to EIC, and cervical dilation (cm) and GA at placement.
Results:
122 patients underwent an EIC; 93 (76.2%) met inclusion criteria. 38 patients (40.9 %) received SDR, and 55 (59.1%) received MDR. Ninety-five percent of patients received indomethacin. The MDR group had a higher amniocentesis rate (54 vs 30%, p=0.02) and baseline cervical dilation (1 cm [IQR 1 – 2] vs 1 cm [IQR 1 – 1]). Unadjusted GL (88 vs 106 days, mean difference -18 d, p=0.02) and delivery GA (33.3 vs. 35.6 weeks, mean difference -2.3 weeks, p=0.04) were lower in the MDR group. However, in the adjusted model, there was no significant difference in mean GL (-10.5 days, p=0.20, Figure) or delivery GA (-1.5 weeks, p=0.19, Table). Results were similar when adjusting for vaginal progesterone use.
Conclusion:
A single dose of antibiotic prophylaxis is associated with similar GL to a multidose regimen when adjusting for other clinical factors. Limitations of our study include small sample size and that our model may not fully account for unobserved risk differences between the groups.
