Prognostic factors and complication rates for cervical cerclage: a review of 482 cases.

Charts from 482 singleton pregnancies undergoing cerclage placement in patients over a 6-year period were reviewed. Cervical dilatation at time of surgery, number of previous spontaneous losses, and gestational age at placement were key determinants of outcome. The most frequent complication, premature rupture of the membranes, ultimately occurred in 38% of patients. The 6.6% infection rate was increased in patients undergoing emergent versus elective surgery (12.7% vs 4.7%, p less than 0.005) and in patients at increased dilatation at time of surgery (5.7% for less than or equal to 2 cm vs 41.7% for greater than 2 cm, p less than 0.005). McDonald and Shirodkar procedures had similar obstetric outcomes in patients undergoing their first cerclage. The subgroup of patients with prior cerclage surgery showed improved birth weight when the Shirodkar procedure was performed instead of the McDonald cerclage (mean birth weight 3020 vs 2470 gm, p less than 0.005). An increased rate of primary cesarean section was found in the Shirodkar group (31% vs 17%, p less than 0.005). Complication rates and pregnancy outcome appear to reflect cervical dilatation more than gestational age at time of surgery.