Preoperative Versus Perioperative Antibiotic Administration for Examination-Indicated Cerclage.

Optimal antibiotics for examination-indicated cerclage are unknown. We performed a retrospective cohort study of examination-indicated cerclage from 2017 to 2023 to explore how time from examination-indicated cerclage until delivery (latency) differs by exposure to preoperative compared with perioperative (preoperative and postoperative) antibiotics. Exclusion criteria included multiple gestation, more than one cerclage, stillbirth or abortion, or no delivery data. Latency was analyzed with Cox proportional hazards regression adjusted for gestational age at cerclage, amniocentesis, and preoperative cervical dilatation. Of 89 individuals who underwent an examination-indicated cerclage, 37 (41.6%) received preoperative and 52 (58.4%) received perioperative antibiotics. Unadjusted median (interquartile range) latency was 116 (87-128) days after preoperative and 98 (53-117) days after perioperative antibiotics (P=.01). In adjusted analyses, there was no difference in latency (adjusted hazard ratio for perioperative antibiotics 1.28, 95% CI, 0.81-2.02). Our findings should prompt prospective work to identify antibiotics for examination-indicated cerclage that optimize gestational latency.