Background: Gestational diabetes mellitus was associated with increased risks of complications during pregnancy and delivery. The efficacy of probiotics for preventing atopic disease among overweight and obese pregnant women has not been a unified conclusion. Therefore, we aimed to determine the efficacy and safety of probiotics supplementation for overweight and obese pregnant women. Methods: We searched the Cochrane Library, Embase, PubMed, and Web of Science for randomized controlled trials from the earliest publication date available to September 23, 2020, regardless of language or publication status. Two reviewers independently extracted data with a standardized form. When disagreements arose, a third investigator was consulted. Data was pooled using the generic inverse variance method and expressed as mean differences and relative risk with 95% confidence interval (CI). Heterogeneity was measured and quantified by I-2 statistic. Results: There were no significant differences between probiotics and placebo on GDM (RR = 1.03; 95% CI, 0.81-1.30; P = 0.821; I-2 = 38.7%, P = 0.180), excess gestational weight gain (RR = 0.92; 95% CI, 0.79 -1.06; P = 0.223; I-2 = 91.2%, P = 0.001) and neonatal birth weight (WMD = 28.47; 95% CI, -34.80-91.73; P = 0.383; I-2 = 4.5%, P = 0.381). In addition, probiotics might increase the risk of preeclampsia including superimposed (RR = 1.91; 95% CI, 1.03-3.55; P = 0.001; I-2 = 0.0%, P = 0.994). Conclusions: Probiotics had no better efficacy for prevention of atopic disease in overweight or obese pregnant women. In contrast, excessive probiotics supplementation might increase the risk of preeclampsia. More data will be necessary to determine the prevention efficacy of probiotics with consideration of real-world and other epidemiological settings. (C) 2022 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.