Abstract:

Objective This meta-analysis aimed to systematically summarize the risk factors associated with preterm birth in twin pregnancies. Methods We comprehensively searched the following electronic databases from inception to August 2025: China National Knowledge Infrastructure (CNKI), WanFang Database, VIP Database, China Biology Medicine disc (CBM), PubMed, Embase, Cochrane Library, and Web of Science. Literature published on the risk factors for preterm birth in twin pregnancies was included. Two researchers independently performed data extraction and quality assessment. Meta-analysis was conducted using RevMan 5.4 and Stata 17.0 software. Results A total of 10 studies involving 4, 993 participants were included. The meta-analysis identified the following significant risk factors for preterm birth in twin pregnancies: monochorionicity (OR=2.34, 95%CI: 1.58-3.48), gestational hypertension (OR=3.10, 95%CI: 2.48-3.87), premature rupture of membranes (OR=3.68, 95%CI: 1.06-12.81), uterine scar (OR=1.96, 95%CI: 1.51-2.53), chorioamnionitis (OR=2.72, 95%CI: 1.50-4.93), abnormal amniotic fluid (OR=3.29, 95%CI: 2.11-5.13), umbilical cord abnormalities (OR=3.21, 95%CI: 1.43-7.23), and vaginitis (OR=3.40, 95%CI: 1.74-6.66). Body mass index (BMI) was found to be a protective factor (OR=0.88, 95%CI: 0.81-0.95). Conclusion Monochorionicity, gestational hypertension, premature rupture of membranes, uterine scar, chorioamnionitis, abnormal amniotic fluid, umbilical cord abnormalities, and vaginitis are identified as risk factors for preterm birth in twin pregnancies. It is recommended that clinicians actively screen for these high-risk factors in twin pregnancies and implement timely interventions to prevent preterm birth.

Key words: pregnancy, twin, preterm birth, risk factors, meta-analysis