Interventions designed to reduce excessive gestational weight gain can reduce the incidence of gestational diabetes mellitus: A systematic review and meta-analysis of randomised controlled trials

Aims: To (i) evaluate the global impact of interventions designed to prevent excessive gestational weight gain (eGWG) on the incidence of gestational diabetes (GDM), and (ii) examine whether the effects differ by pre-conception body mass index (BMI) or ethnicity. Methods: A systematic search of randomised controlled trials (RCTs) with a primary or secondary aim to reduce eGWG was conducted in seven international and three Chinese databases without date limits. Meta-analysis data are reported as relative risk (RR) for GDM incidence for interventions including: diet, physical activity (PA), and lifestyle (diet and PA). Results: Forty-five studies were included, 37 in the meta-analyses. Diet and PA interventions reduced GDM risk by 44% (RR: 0.56, 95% CI: 0.36–0.87) and 38% (RR: 0.62, 95% CI: 0.50–0.78), respectively. Lifestyle interventions and BMI didn't significantly alter GDM risk. PA interventions from Southern-Europe reduced GDM risk by 37% (RR: 0.63, 95% CI: 0.50–0.80). Whereas, diet and lifestyle interventions conducted in Asia reduced GDM risk by 62% (RR: 0.38, 95% CI: 0.24–0.59) and 32% (RR: 0.68, 95% CI: 0.54–0.86), respectively. Conclusion: Diet and PA interventions designed to reduce GWG are more effective than standard care in reducing the incidence of GDM, although the effect varies by region and BMI. The ‘one size fits all’ approach is not supported.