Excessive gestational weight gain prior to glucose screening and the risk of gestational diabetes: a meta-analysis

Aims/hypothesis Excessive gestational weight gain (GWG) may be a risk factor for gestational diabetes mellitus (GDM). We aimed to study the association between excessive GWG (defined according to Institute of Medicine recommendations) prior to GDM screening, and GDM. Methods We systematically searched four electronic databases from 1990 until September 2014 for observational studies published in English or German that reported an association between excessive GWG and GDM as the outcome. Random effects meta-analyses were performed to provide a pooled estimate of the OR comparing the risk of GDM in women with and without excessive GWG. Results A total of eight studies involving 13,748 participants were included. The pooled analysis of unadjusted OR yielded a summary OR of 1.40 (95% CI 1.21, 1.61; p < 0.001) with low between-study heterogeneity (I (2) = 16.7%). A sensitivity analysis based on four studies reporting adjusted effect estimates revealed similar results (OR 1.42; 95% CI 1.20, 1.68; p < 0.001; I (2) = 0%). No evidence was found that the effect of GWG on GDM differs depending on maternal pre-pregnancy BMI category. A funnel plot did not indicate substantial publication bias. Conclusions/interpretation Avoiding excessive weight gain in pregnancy prior to the GDM screening test may be a potential strategy to reduce GDM risk. Meta-analysis registration www.crd.york.ac.uk/PROSPERO CRD42014008802