Does increasing body mass index affect cerclage efficacy?

Objective:to study the relationship between body mass index (bmi) and gestational age (ga) at delivery in patients with cervical insufficiency (ci) undergoing cerclage.study design:we accessed a database of patients with singleton gestations undergoing cerclage (n=168) for a well-characterized history of ci, shortened cervix <2.5 cm with a history of prior preterm delivery or prolapse of membranes through the external os. univariate and multivariate logistic regression analysis were performed to compare obstetrical outcomes between obese and normal-weight patients.result:prior preterm delivery <35 weeks in obese vs normal-weight patients was significantly higher (44% vs 9%), odds ratio=6.9 (95% ci: 2.5, 18.5), with lower mean ga at delivery (32.6±7.0 vs 37.2±3.4 weeks, p<0.001). after controlling for confounders, bmi remained significantly predictive of prematurity (coefficient: −0.12, adjusted r2=0.24), such that every additional 1 unit of bmi was associated with a 1-day reduction in ga at delivery (p=0.03).conclusion:an inverse correlation exists between bmi and ga at delivery in patients with ci receiving cerclage. the findings are unexpected given the protective effect of obesity on spontaneous preterm delivery.