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/m(2) [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. (C) 2021 by American Society for Reproductive Medicine.