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Lookup NU author(s): Dr Anna Boath, Professor Nicola HeslehurstORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
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: The main outcomes were gestational diabetes by any criteria and by the National Institute for Health and Care Excellence. Other outcomes were gestational diabetes as per International Association of Diabetes in Pregnancy Study Group and maternal and perinatal outcomes. We performed a two-stage random-effects individual participant data meta-analysis to obtain summary estimates (odds ratio) with 95% confidence intervals. Study quality of included trials was assessed, and heterogeneity summarised using τ2. 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: Ninety-two trials (32,284 women) were included; 54 (23,698 women) provided individual participant data. Lifestyle interventions reduced the odds of gestational diabetes (any criteria) by 10% in individual participant data trials (odds ratio 0.90, 95% confidence interval 0.80 to 1.02, 54 studies, 23,361 women), and the findings reached statistical significance when non-individual participant data were included (odds ratio 0.81, 95% confidence interval 0.73 to 0.89, 92 studies, 31,947 women). Physical activity significantly reduced the odds of gestational diabetes by 36% (odds ratio 0.64; 95% confidence interval 0.48 to 0.84), and diet by 19% (odds ratio 0.81; 0.69 to 0.96), but not mixed interventions. Women with middle (odds ratio 0.68, 95% confidence interval 0.51 to 0.90) and high educational level (odds ratio 0.71, 95% confidence interval 0.54 to 0.93) benefited more than those with low educational status, and no differences by maternal body mass index, age, parity or ethnicity. There was no significant reduction in gestational diabetes defined by National Institute for Health and Care Excellence criteria (odds ratio 0.98, 95% confidence interval 0.84 to 1.13) in individual participant data trials. For gestational diabetes defined using International Association of Diabetes in Pregnancy Study Group criteria, interventions reduced gestational diabetes by 14% (odds ratio 0.86, 95% confidence interval 0.75 to 0.97, τ2 = 0.00, 16 studies, 6174 women) in individual participant data trials and by 17% (odds ratio 0.83, 95% confidence interval 0.72 to 0.95, τ2 = 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: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR129715) and is published in full in Health Technology Assessment; Vol. 30, No. 39. See the NIHR Funding and Awards website for further award information.During pregnancy, not eating well, not moving enough, and being overweight can lead to a condition called ‘gestational diabetes’. It is when mothers have high sugar levels for the first time. This can cause problems for both the mother and the baby during pregnancy and later in life. Being more active and eating healthily could lower the chances of mothers developing ‘gestational diabetes’. However, these changes might help some mothers more than others. It could depend on things like how much they weigh, their age, how many babies they have had before, their ethnicity, and education level. We wanted to see if improving physical activity and diet – ‘lifestyle interventions’ – could prevent gestational diabetes, and whether all mothers benefit. We looked at individual information from almost 24,000 women in different studies from all over the world, that recruited a total of about 32,000 women. Some studies looked at changes in physical activity, some at diet changes and some at both. When we put all this information together, we found that lifestyle interventions could reduce the odds of gestational diabetes by about 10% when considering only studies that shared their data, although some women could see a slight 2% increase in risk. Including information from studies that did not share data, showed greater benefit, reducing the odds by about a fifth. Lifestyle interventions seemed to work better in mothers who were more educated, so support is needed to make them work for everyone. Physical activity seemed to be the most effective intervention, and reduced caesarean births, having babies who were either too small or too big for their age, and the need for special care after birth. Eating better also lowered the risk of having a baby too early. Although lifestyle intervention was more expensive to the NHS, it lowered the chances of gestational diabetes.
Author(s): Allotey J, Coomar D, Ensor J, Ogwulu CO, Calvo GR, Monahan M, Kabeya V, McNeill R, Boath A, Mahmoud G, Harrison C, Khomami MB, Teede H, Heslehurst N, Hitman GA, Simpson SA, Nirantharakumar K, Dodds J, Allison KC, Shen G, Petrella E, Facchinetti F, Vinter C, Pelaez M, Jensen DM, Motahari-Tabari NS, Kinnunen TI, Ruiz JR, Bogaerts A, Renault KM, Kothari A, Cecatti JG, McAuliffe FM, Phelan S, Poston L, Betran AP, Moss N, Iliodromiti S, Austin F, de la Torre NG, Pascual ALC, Zamora J, Roberts T, Riley RD, Thangaratinam S
Publication type: Article
Publication status: Published
Journal: Health Technology Assessment
Year: 2026
Volume: 30
Issue: 39
Pages: 1-252
Print publication date: 01/05/2026
Acceptance date: 31/05/2025
Date deposited: 26/05/2026
ISSN (electronic): 2046-4924
Publisher: NIHR Journals Library
URL: https://doi.org/10.3310/GJST1327
DOI: 10.3310/GJST1327
PubMed id: 42117518
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