Mean differences in maternal body mass index and recurrent pregnancy loss: a systematic review and meta-analysis of observational studies

Objective: To investigate the association of maternal body mass index (BMI) and recurrent pregnancy loss (RPL). Design: Systematic review and meta-analysis. Setting: Not applicable. Patient(s): A total of 3,833 women with RPL and 4,083 women as controls. Intervention(s): Studies were identified through a search of PubMed, Embase, Scopus, and Cochrane. Main Outcome Measure(s): The primary outcome of interest was RPL using the mean differences in maternal BMI as the predictor variable. The results of the meta-analysis were reported as the mean difference with a 95% confidence interval. Result(s): In total, 892 studies were reviewed. Pooled data from 25 studies suggested that the maternal BMI of women with a history of recurrent pregnancy loss was significantly higher than the BMI of controls, mean difference 0.7 kg/m² [95% confidence interval 0.2–1.3]. Conclusion(s): These findings supported an association between maternal BMI and RPL. Large prospective studies are needed to evaluate the influence of maternal BMI on pregnancy outcomes in women with RPL.