Twenty studies were included in the meta-analysis. The unadjusted ORs of
developing GDM were 2.14 (95% CI 1.82–2.53), 3.56 (3.05–4.21), and 8.56 (5.07–16.04)
among overweight, obese, and severely obese compared with normal-weight pregnant women,
respectively. The meta-regression analysis found no evidence that these estimates were affected
by selected study characteristics (publication date, study location, parity, type of data collection
[retrospective vs. prospective], and prevalence of GDM among normal-weight women).