Background: Physical inactivity and suboptimal diet in pregnancy are important modifiable risk factors for gestational diabetes, a major contributor to pregnancy complications. Objectives: We aimed to assess the effects of physical activity and/or diet-based lifestyle interventions during pregnancy on gestational diabetes and if these vary by maternal (body mass index, age, parity, ethnicity, education) and intervention characteristics using individual participant data meta-analysis of randomised trials, and a cost-effectiveness analysis. Data sources: International Weight Management in Pregnancy Collaborative Network database was updated by searching major databases from February 2017 to March 2022. Review methods: . Where possible, we added the aggregate data from non-individual participant data trials to the meta-analysis. We ranked interventions by effectiveness using network meta-analysis and undertook model-based economic evaluation to assess cost-effectiveness. The cost-effectiveness analysis took an NHS cost perspective compared an overall lifestyle intervention versus usual care with a time horizon covering the beginning of pregnancy until the discharge of the mother and infant from the hospital following delivery. Results: = 0.01, 25 studies, 7883 women) when non-individual participant data trials were added. Overall, physical activity reduced caesarean section (odds ratio 0.83; 0.72 to 0.96), small-for-gestational age (odds ratio 0.72; 0.56 to 0.92) and large-for-gestational age babies (odds ratio 0.81; 0.71 to 0.94); diet-based interventions reduced any preterm birth (odds ratio 0.37; 0.20 to 0.68) compared to controls. No differences were observed for other outcomes. Lifestyle interventions were on average more expensive and more effective at averted gestational diabetes and major outcome averted compared to usual care. Limitations: We could not identify the specific intervention components and delivery methods associated with improved outcomes, due to variations in reporting. Conclusion: Lifestyle interventions in pregnancy prevent gestational diabetes, and the effects vary according to the definition of gestational diabetes. Physical activity-based interventions may be the most effective. Future work: Lifestyle interventions should be implemented and evaluated in routine clinical practice to prevent gestational diabetes, with additional support for women with low socioeconomic status. Study registration: This study is registered as PROSPERO CRD42020212884. www.crd.york.ac.uk/PROSPERO/view/CRD42020212884. Funding: ; Vol. 30, No. 39. See the NIHR Funding and Awards website for further award information.
Allotey et al. (Thu,) studied this question.