Am J Obstet Gynecol MFM. 2025 Oct 22:101818. doi: 10.1016/j.ajogmf.2025.101818. Online ahead of print.
ABSTRACT
BACKGROUND: Physical exam indicated-cerclage is an intervention offered to prolong pregnancy in the setting of painless cervical dilation prior to 24 weeks. One randomized clinical trial (RCT) showed an increased incidence of pregnancy prolongation by at least 28 days among participants who received perioperative indomethacin and cefazolin in the setting of a physical exam-indicated cerclage compared to those who did not receive those perioperative medications. Prospective studies suggest that prophylactic azithromycin may increase latency in the setting of cervical shortening, but this has not been studied in a controlled manner in patients undergoing physical exam-indicated cerclage.
OBJECTIVE: The aim of our study is to determine whether the addition of perioperative azithromycin to cefazolin and indomethacin for physical exam-indicated cerclage increases latency to delivery compared to perioperative cefazolin and indomethacin alone.
STUDY DESIGN: This was an open-label multicenter RCT of individuals with singleton gestations who were undergoing a physical exam-indicated cerclage between December 2021 and September 2023 at four sites across the United States. The study was IRB approved and registered at clinicaltrials.gov (NCT05132829). Participants were randomized 1:1 via a computer-generated randomization sequence stratified by site to standard of care (cefazolin 1-2 gm IV and indomethacin 50mg preoperatively followed by 2 additional doses at 8 and 16 hours postoperatively, control arm) or standard of care plus azithromycin (azithromycin 1000mg IV in addition to cefazolin and indomethacin described in the control group, azithromycin arm). The primary outcome was gestational latency (days) from cerclage placement to delivery. Secondary outcomes include preterm birth, gestational age at delivery, chorioamnionitis, and neonatal morbidity and mortality.
RESULTS: A total of 82 pregnant individuals were assessed for eligibility and 54 participants were randomized, 27 to control and 27 to the azithromycin arm. In the primary intention-to-treat analysis, the median gestational latency from cerclage placement to delivery did not differ between the intervention and control groups (92 [45-118] vs 85 [20-123] days p=0.93). Furthermore, there were no statistically significant differences found in any of the secondary obstetric or neonatal outcomes.
CONCLUSION: A single perioperative dose of azithromycin in addition to standard of care cefazolin and indomethacin does not improve latency to delivery or other perinatal outcomes compared to standard of care alone in singleton gestations undergoing a physical exam-indicated cerclage.
PMID:41135925 | DOI:10.1016/j.ajogmf.2025.101818
