Abstract
Objective: To assess whether type of suture material affects cerclage efficacy for preterm birth (PTB) prevention. Methods: Secondary analysis of a multicenter trial of ultrasound-indicated cerclage for short cervical length (CL), in which women with prior spontaneous PTB at 16-33 6/7 weeks, a singleton gestation and CL < 25 mm between 16-22 6/7 weeks, were randomized to McDonald cerclage or no cerclage. Outcomes of women who underwent cerclage were analyzed by type of suture material, comparing polyester braided thread (Mersilene (TM) or Ethibond (TM) to Mersilene tape (TM). Primary outcome was PTB < 35 weeks. Results: 138 women underwent McDonald cerclage: 84(61%) received polyester braided thread and 46 (33%) Mersilene tape (TM). Eight (6%) received monofilament suture and were excluded from analysis. Rates of PTB < 35 weeks were similar, 35% for polyester braided thread vs 24% for Mersilene tape (TM) (p = .24). Birth gestational age was also similar among the 2 groups (p = .18). Conclusion: Type of suture material may not affect ultrasound-indicated cerclage efficacy in high-risk women with short CL, but further study is needed. Polyester braided thread (Mersilene (TM) or Ethibond (TM)) and polyester braided Mersilene tape (TM) seem to have similar efficacy.