Risk factors for premature rupture of membranes in pregnant women: a systematic review and meta-analysis

Objective To identify risk factors for premature rupture of membranes (PROM) in pregnant women. Design Systematic review and meta-analysis. Data sources Web of Science, PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang Database, Chinese Scientific Journal Database (VIP) and China Biology Medicine Disc were searched from inception to October 2022. Eligibility criteria Cross-sectional, case–control and cohort studies published in English or Chinese that reported the risk factors for PROM were eligible for inclusion. Data extraction and synthesis Two reviewers independently extracted the data and evaluated the risk of bias using the Newcastle–Ottawa Scale and American Agency for Healthcare Research and Quality tools. Analyses were performed using RevMan 5.4 software, and heterogeneity was assessed using χ 2 tests and I 2 statistics. The sensitivity analyses included a methodological transition between fixed-effect and random-effect models and the systematic stepwise exclusion of studies. Results A total of 21 studies involving 18 174 participants with 18 risk factors were included. The significant risk factors were low Body Mass Index (BMI) (OR 2.18, 95% CI 1.32 to 3.61), interpregnancy interval (IPI) <2 years (OR 2.99, 95% CI 1.98 to 4.50), previous abortion (OR 2.35, 95% CI 1.76 to 3.14), previous preterm birth (OR 5.72, 95% CI 3.44 to 9.50), prior PROM (OR 3.95, 95% CI 2.48 to 6.28), history of caesarean section (OR 3.06, 95% CI 1.72 to 5.43), gestational hypertension (OR 3.84, 95% CI 2.36 to 6.24), gestational diabetes mellitus (GDM) (OR 2.16, 95% CI 1.44 to 3.23), abnormal vaginal discharge (OR 2.17, 95% CI 1.45 to 3.27), reproductive tract infection (OR 2.16, 95% CI 1.70 to 2.75), malpresentation (OR 2.26, 95% CI 1.78 to 2.85) and increased abdominal pressure (OR 1.45, 95% CI 1.07 to 1.97). The sensitivity analysis showed that the pooled estimates were stable. Conclusions This meta-analysis indicated that low BMI, IPI <2 years, previous abortion, previous preterm birth, prior PROM, history of caesarean section, gestational hypertension, GDM, abnormal vaginal discharge, reproductive tract infection, malpresentation and increased abdominal pressure might be associated with a greater risk of PROM. Associations between smoking status, short cervical length, fine particulate matter (PM 2.5 ) and PROM require further investigation. PROSPERO registration number CRD42022381485.