The effectiveness of ultrasound-indicated cerclage for the reduction of extreme preterm birth in twin pregnancies with a short cervix: a systematic review and meta-analysis: Short title: Effectiveness of cerclage in twin pregnancies with a short cervix.

Objective: Evaluate the effectiveness of cervical cerclage in women with a twin pregnancy and a midpregnancy asymptomatic short cervix (≤25mm), in preventing preterm birth (PTB) and improving neonatal outcomes.

Data Sources: Systematic searches were conducted in MEDLINE, Embase, Web of Science, Scopus, and Cochrane Library up to April 17 2023, updated in September and February 2024.

Study Eligibility Criteria: Included were RCTs, cohort studies and case-control studies comparing cerclage vs.