Diet and lifestyle interventions for obese pregnant women
Authors: Shakila Thangaratinam
Journal: The Lancet Diabetes & Endocrinology (2015)

Improvement of health outcomes in obese and overweight individuals is a worldwide research priority. Lifestyle interventions in pregnancy have the potential to minimise complications in both mother and baby.1Thangaratinam S Rogozinska E Jolly K et al.Effects of interventions in pregnancy on maternal weight and obstetric outcomes: meta-analysis of randomised evidence.BMJ. 2012; 344: e2088Crossref PubMed Scopus (579) Google Scholar In The Lancet Diabetes & Endocrinology, Lucilla Poston and colleagues in The UPBEAT Trial Consortium2Poston L Bell R Croker H et al.on behalf of the UPBEAT Trial ConsortiumEffect of a behavioural intervention in obese pregnant women (the UPBEAT study): a multicentre, randomised controlled trial.Lancet Diabetes Endocrinol. 2015; (published online July 10.)http://dx.doi.org/10.1016/S2213-8587(15)00227-2Google Scholar report findings of one of the largest randomised trials to date to assess the effects of lifestyle interventions in obese pregnant women. In the UPBEAT study, Poston and colleagues assessed a complex behavioural intervention based on a healthy diet and increased physical activity and compared it with standard antenatal care in the UK. The study focused primarily on the incidence of gestational diabetes and large-for-gestational-age babies; the authors also assessed other clinically important outcomes such as pre-eclampsia, mode of delivery, and preterm birth, as well as neonatal outcomes, maternal and fetal weight-related outcomes, glycaemic status, dietary intake, and measures of physical activity. The intervention in obese pregnant women did not reduce the incidence of gestational diabetes (risk ratio 0·96, 95% CI 0·79–1·16; p=0·68) or large-for-gestational-age babies (1·15, 0·83–1·59; p=0·40). No differences between groups were noted for several of the other clinical outcomes, measures of glycaemic status (including blood glucose concentrations), or the need for insulin. Total gestational weight gain was lower in the intervention group than in controls (mean difference −0·42 kg, 95% CI −0·75 to −0·09; p=0·013), an effect seen by 28 weeks of gestation. In women who received the intervention, a significant improvement was reported in dietary pattern, and physical activity was also increased. The UPBEAT trial has added to growing evidence showing the ineffectiveness of mixed interventions based on diet and lifestyle on the incidence of gestational diabetes and large babies, particularly in overweight and obese women. The study findings accord with those of previous systematic reviews,3Rogozińska E Chamillard M Hitman GA Khan KS Thangaratinam S Nutritional manipulation for the primary prevention of gestational diabetes mellitus: a meta-analysis of randomised studies.PLoS One. 2015; 10: e0115526Crossref Scopus (73) Google Scholar in which mixed interventions based on both diet and physical activity did not reduce the incidence of gestational diabetes. Interventions based mainly on diet, some with restricted energy intake, have shown a beneficial effect in prevention of gestational diabetes.1Thangaratinam S Rogozinska E Jolly K et al.Effects of interventions in pregnancy on maternal weight and obstetric outcomes: meta-analysis of randomised evidence.BMJ. 2012; 344: e2088Crossref PubMed Scopus (579) Google Scholar However, the studies were small and did not assess gestational diabetes as a primary outcome. The LIMIT trial, which included overweight and obese pregnant women, also reported no beneficial effect of diet and physical activity on large-for-gestational-age fetuses or gestational diabetes.4Dodd JM Turnbull D McPhee AJ et al.Antenatal lifestyle advice for women who are overweight or obese: LIMIT randomised trial.BMJ. 2014; 348: g1285Crossref PubMed Scopus (349) Google Scholar In a Cochrane review,5Muktabhant B Lawrie TA Lumbiganon P Laopaiboon M Diet or exercise, or both, for preventing excessive weight gain in pregnancy.Cochrane Database Syst Rev. 2015; 6 (CD007145)PubMed Google Scholar a reduction in excess weight gain during pregnancy was reported with diet and lifestyle interventions, but gestational diabetes was not assessed as an outcome. Although a lower weight gain was noted in the intervention group compared with standard care by 28 weeks of gestation in the UPBEAT study, this finding did not translate into clinical benefits. Poston and colleagues noted a possible reluctance of obese women to follow the intervention, with only a fifth of all eligible mothers participating in the trial. Whether women with a previous history of gestational diabetes will be more willing to adopt the planned intervention, or whether there will be a differential effect in this high-risk group, is not known. Furthermore, in the absence of reliable biomarkers to assess adherence, the actual proportion of mothers who followed the dietary advice can only be estimated from patient-reported dietary questionnaires. Currently in the USA and many other countries, pregnant women are recommended various weight gain targets during pregnancy according to their BMI status.6Rasmussen KM Yatkine AL Weight gain during pregnancy: reexamining the guidelines. The National Academies Press, Washington2009Google Scholar In the UK, NICE (The National Institute for Health and Care Excellence) recommends referral of obese pregnant women to a dietician or a health-care professional but does not recommend regular weighing in pregnancy.7NICEDietary interventions and physical activity interventions for weight management before, during and after pregnancy (PH27). National Institute for Health and Care Excellence, London2010Google Scholar Based on the UPBEAT study findings, a change in current UK guidelines is not needed. Women should be informed that although a healthy diet and lifestyle could minimise weight gain in pregnancy, there is no robust evidence for improvement in outcomes such as gestational diabetes or large-for-gestational-age babies. However, a reduction in excess weight gain in normal weight and overweight mothers has the potential to decrease postpartum weight retention and minimise the risk of beginning future pregnancies as obese individuals. Prevention of obesity needs to be prioritised equally with efforts to reduce complications in obese pregnant women. Future research should investigate the association between clinical outcomes and weight gain within recommended targets for various BMI groups. Standardisation of reporting of outcomes is required for meaningful interpretation of evidence, and clinical applicability of findings. I am the chief investigator of the National Institute for Health Research project HTA–12/01/50 (effects of weight management interventions on maternal and fetal outcomes in pregnancy: individual patient data [IPD] meta-analysis of randomised trials and model-based economic evaluation). The UPBEAT study contributes data to the IPD. Effect of a behavioural intervention in obese pregnant women (the UPBEAT study): a multicentre, randomised controlled trialA behavioural intervention addressing diet and physical activity in women with obesity during pregnancy is not adequate to prevent gestational diabetes, or to reduce the incidence of large-for-gestational-age infants. Full-Text PDF Open Access