An overview of evidence on diet and physical activity based interventions for gestational weight management

Background. Maternal obesity and excessive gestational weight gain are associated with adverse maternal and neonatal outcomes. Currently, 20% of mothers in the UK are obese and the prevalence of obesity is increasing. In the UK, there is a lack of evidence or guidelines quantifying an ideal gestational weight gain or strategies to encourage women to remain within these limits.

Aim. To provide an overview of systematic evidence which have synthesised the results from trials on the efficacy of gestational weight management interventions, and to discuss key components of effective diet or physical activity interventions in improving pregnancy and birth outcomes.

Method. English language systematic reviews published after the NICE guidance on weight management before, during and after pregnancy (2010) were searched for using Medline.

Findings. A total of 12 systematic reviews were identified. Most reported interventions had an effect on reducing weight gain, however, included studies were often of poor quality.

Conclusion. Dietary interventions seem to be more effective in reducing gestational weight gain with some improvement in clinical outcomes (for example, reducing the risk of gestational diabetes, gestational hypertension and shoulder dystocia). Physical activity also has a role to play, however, in light of low compliance and concerns over limited understanding of its full impact on fetal growth and birthweight, more robust investigations are required to address the balance between its benefits, acceptability and impact on birthweight.

Implications. Further research is required to identify optimum gestational weight gain and the particular components of interventions that have been shown to be effective and safe in reducing this during pregnancy. Midwives, with their key role in health promotion, should be offered support and training in keeping up to date with the growing body of evidence on gestational weight management and behaviour change techniques to promote a healthy lifestyle for women and their families.