Shirodkar cerclage is more effective than mcdonald for the prevention of preterm birth

Introduction: Data on the efficacy of the McDonald (MD) and Shirodkar (SK) cervical cerclage to reduce preterm birth (PTB) is inconclusive. We aimed to compare the efficacy of these two surgical techniques in pregnancies with history and ultrasound-indicated cervical cerclage. Methods: A retrospective cohort study of patients who underwent history or ultrasound-indicated cerclage between 2007 and 2014. PTB rates were compared among pregnancies with either a MD or SK cerclage. Kaplan-Meier Survival Analysis was performed to determine the latency between cerclage placement and delivery. Selected neonatal outcomes were compared between the two groups. Chi-square test and One-Way ANOVA on Ranks were used to analyze the data. Results: Of 306 MD and 43 SK cerclages, 185 (60.5%) and 34 (79.1%) were history-indicated, and 121 (39.5%) and 9 (20.9%) were ultrasound-indicated, respectively. PTB, 32 weeks occurred in 100 (32.7%) and in 7 (16.3%) of MD and SK (p =.045). PTB, 37 weeks was higher in the MD than in the SK group (58.2% and 41.8%; p =.046). Latency was also different between the groups, (Figure; p =.002) with median latency of 17.7 weeks (95% confidence interval (CI); 16.9, 18.5) for the MD group and 23.0 weeks (95% CI; 22.0, 23.9) for the SK group. Neonatal respiratory distress syndrome was more common in the MD than in the SK group (45.2% versus 13.9%, p =.032). Conclusion: Shirodkar cerclage is associated with improved pregnancy prolongation, lower PTB rates, and better neonatal out-comes compared with McDonald cerclage. A randomized clinical trial to confirm our findings is justified.