Double Versus Single Cervical Cerclage in Women with Cervical Insufficiency: A Systematic Review of Prophylactic and Emergency Indications

Background/Objectives: Cervical insufficiency remains a leading cause of second-trimester pregnancy loss and early preterm birth. Although single-level cerclage techniques such as McDonald or Shirodkar are widely accepted, the potential advantages of double or modified double-level cerclage remain controversial. Methods: This systematic review was conducted in accordance with PRISMA guidelines. Comprehensive searches of PubMed, Embase, Web of Science, and the Cochrane Library (to September 2025) were supplemented by Google Scholar and conference proceedings. Eligible studies included randomized controlled trials, comparative cohort studies, and case series directly comparing double versus single transvaginal cerclage. A total of twenty-six sources were included, spanning randomized trials, comparative cohort studies, published protocols, case series, systematic reviews, conference abstracts, and early technical or historical reports. The primary outcome was preterm birth before 34 weeks; secondary outcomes were GA at delivery, latency, neonatal morbidity and mortality, and maternal complications. Results: Across prophylactic (history- or ultrasound-indicated) settings, double sutures produced outcomes comparable to single-level cerclage without consistent superiority. In contrast, in emergency or exam-indicated cases with advanced cervical dilation or bulging membranes, double or double-level cerclage significantly prolonged latency and reduced very preterm birth (<32–34 weeks). Double-level reinforced techniques (including monofilament-based and modified Wurm-type approaches) showed improved mechanical support and lower neonatal intensive-care admission. Case series further demonstrated successful rescue procedures beyond 24 weeks, indicating expanded surgical feasibility in selected patients. Conclusions: While double cerclage yields similar results to single cerclage in prophylactic use, it appears advantageous in high-risk or emergency scenarios. Comparative analyses suggest that combined mechanical and infection-controlled approaches may improve cervical competence and prolong gestation in selected patients. Ongoing multicenter randomized trials are needed to establish its definitive role in modern obstetric practice.