Comparison of Vaginal Progesterone and Cervical Cerclage for Short Cervix in Twin Pregnancies

Abstract

Introduction: Twin pregnancies have higher preterm birth risk. Both vaginal progesterone and cerclage are used for a short cervix (<25 mm), but evidence is limited due to smaller sample sizes.
Methods: Systematic review and network meta-analysis of randomized trials and adjusted cohort studies. Outcomes: preterm birth <34 weeks, neonatal composite morbidity.
Results: Seven trials (n=850 twin pregnancies) were included. Vaginal progesterone reduced preterm birth <34 weeks compared to placebo (relative risk 0.74). Cerclage showed no significant benefit over placebo (RR 0.92). In network comparison, progesterone was superior to cerclage for prevention (P-score 0.86 vs. 0.45). Neonatal outcomes mirrored these findings.
Discussion: The lack of cerclage efficacy in twins may be due to different cervical shortening mechanisms (overdistension vs. structural weakness). Progesterone is easier to implement and has fewer procedure-related risks.
Conclusions: Vaginal progesterone, not cerclage, is effective for reducing preterm birth in twin pregnancies with a short cervix. Cerclage should not be routinely offered in this population.