(1142) Not all cerclages are equal: a high‑volume cohort reveals indication‑driven differences in pregnancy outcomes

Objective:
To evaluate whether pregnancy outcomes differ among women undergoing cervical cerclage based on the indication for the procedure: history-indicated, ultrasound-indicated, or physical examination–indicated cerclage.

Study Design:
We conducted a retrospective cohort study of all women who underwent cervical cerclage at our institution between 2014-2024. Women were classified according to cerclage indication: History-indicated, Ultrasound-indicated, or Physical examination–indicated. Baseline characteristics and pregnancy outcomes were extracted from electronic medical records. Descriptive statistics compared demographic and obstetric history variables between groups. The primary outcome was preterm birth (< 37 weeks). Adjusted risk ratios (aRR) were estimated using log-binomial regression for parity and history of prior preterm birth.

Results:
Of 440 women, 349 (71.8%) had history-indicated cerclage, 79 (16.3%) ultrasound-indicated, and 12 (2.5%) physical examination–indicated cerclage, often performed in women presenting with advanced cervical dilation or bulging membranes. Median gestational age at delivery was 38.4, 37.9, and 37.6 weeks, respectively (p=0.0038). Preterm birth (< 37 weeks) occurred in 23.8%, 36.7%, and 41.7% of the groups (p=0.031).  After adjusting for previous preterm birth history and parity, women receiving ultrasound or physical examination–indicated cerclage had a significantly increased risk of preterm birth compared with the history-indicated cerclage group (aRR 1.53, 95% CI 1.07–2.18, p=0.019). Secondary outcomes followed a similar trend, with the poorest outcomes observed in the ultrasound and physical examination indicated groups.

Conclusion:
Indication for cervical cerclage is strongly associated with pregnancy outcomes. Women undergoing ultrasound or physical examination–indicated cerclage remain at a higher risk of preterm birth despite intervention compared with those receiving prophylactic cerclage. These findings highlight the importance of early identification of high-risk women who may benefit from timely prophylactic cerclage placement.