A systematic review and meta-analysis of exercise-based intervention to prevent gestational diabetes in women with overweight or obesity.

Background: There is evidence that exercise may reduce the risk of gestational diabetes mellitus (GDM) and improve other obstetric outcomes in overweight or obese pregnant women. However, the available evidence is of low quality and inconclusive. The purpose of this study is to assess the effects of exercise, compared with usual care, in reducing GDM and other obstetric risks, in overweight and obese pregnant women.

Methods: We searched MEDLINE, Embase, and the Cochrane Library from their inception dates up to August 2022. Randomised studies comparing physical exercise versus routine obstetric care in pregnant women with overweight or obesity (BMI ≥ 25.0). Each abstract and full-text article was independently reviewed by the same two authors. The primary outcome was the incidence of GDM, and the secondary outcomes were excessive weight gain, preterm delivery, and foetal macrosomia. Summary risk ratios (RRs) and 95% confidence intervals (CIs) were calculated.

Main Results: Seven studies covering 1162 patients were identified. Exercise did not reduce the risk of GDM: RR, 0.82 [95% CI, (0.58-1.17)] but subgroup analysis shows a significant benefit among patients adhering to the programs: RR, 0.56 [95% CI, (0.40-0.78)] and no effect among non-adherents: RR, 1.11 [95% CI, (0.82-1.50)]. We did not find a significant effect on excessive weight gain: RR, 0.92 [95% CI, (0.76-1.11)] but there was a reduction in the risk of foetal macrosomia: RR, 0.5 [95% CI, (0.32-0.79)]. Exercise has not been associated with an increased risk of preterm birth: RR, 0.79 [95% CI, (0.44-1.39)].

Conclusions: The present study does not allow us to conclude that structured exercise programs for pregnant women with overweight or obesity leads to a reduction in the risk of gestational diabetes. When exercise program adherence is high, a significant reduction of GDM is observed. These findings will need to be confirmed with large primary trials. A reduction in the incidence of foetal macrosomia has also been observed. TRIAL REGISTRATION: This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO; identifier: CRD42023399004).