Abstract
This systematic overview summarizes the relevant evidence from multiple systematic reviews of the benefits of nonpharmacological interventions for preventing type 2 diabetes mellitus (T2MD) in women diagnosed with gestational diabetes mellitus (GDM). A comprehensive search using the Cochrane Library, CINAHL, EMBASE and MEDLINE via Ovid SP, and PubMed databases was completed on 18 November 2015. Any systematic reviews that evaluated randomized controlled trials (RCTs) with defined nonpharmacological interventions for preventing T2DM in women diagnosed with GDM were eligible for inclusion. The authors independently performed critical appraisals and quality assessments of the included reviews using the AMSTAR tool, and extracted data were converted to coherent values for tabular summarization. Six eligible reviews of diet and/or exercise, breastfeeding, and reminder interventions were identified; however, the methodologies of the reviews varied greatly, and the majority of the evidence suggested unclear bias. We found inconsistent reporting on the rates at which diet and exercise interventions reduced the risk of T2DM progression, but these interventions were found to be effective at reducing glycemic load. Combined diet, exercise, and breastfeeding interventions proved to be effective at returning women to their postpartum weight. Neither diet alone nor exercise alone proved to be effective at lowering the risk of T2DM. Overall, there was no robust evidence to support the hypothesis that nonpharmacological interventions are effective at lowering the risk of T2DM in women diagnosed with GDM, and there was no consistent evidence showing that these interventions improved the predictor outcomes of T2DM, such as glycemic load or anthropometric changes.