A study in BMJ reports that the risk for serious complications, such as pre-eclampsia, diabetes and premature birth can be safely reduced even in overweight and obese pregnant women by following a healthy calorie controlled diet during pregnancy.

Over half of the UK’s female population of reproductive ages is overweight or obese, and up to 40% of European and American women gain more than the recommended weight in pregnancy, which has been associated with numerous serious health problems. Health professionals believe that a woman’s pregnancy is the perfect time to discuss weight management, given that pregnant women are generally more motivated to make changes that benefit both themselves and their baby.

Research leader, Dr Shakila Thangaratinam from Queen Mary’s University of London assessed the impact of diet, exercise, or both on weight gain during pregnancy and any adverse effects on the expectant mother and their unborn baby by analyzing data from over 7,000 women obtained from 44 randomized controlled trials. The team accounted for the study’s designs and quality for minimum bias.

They found that weight management interventions during pregnancy proved effective in reducing the mother’s weight gain, and that diets achieved the largest average weight loss of almost 4 kg in comparison with only 0.7 kg for exercise and 1 kg for a combination of both, diet and exercise. They also discovered that diet was the most effective option in preventing pregnancy complications, including pre-eclampsia, diabetes, high blood pressure and premature birth, although the researchers highlight the fact that the overall evidence rating for these significant results was classed as ‘low to very low’.

However, the findings did prove that interventions are indeed safe and have no adverse impact on the baby’s weight. The researchers conclude that dietary and lifestyle interventions in pregnancy improve outcomes for both mother and infant, but acknowledge that their study was subject to limitations in terms of the lack of data on risk factors, including age, ethnicity and socioeconomic status.

According to experts at London’s St Thomas Hospital in London, opinion in an associated editorial, the evidence to support any specific intervention is still insufficient. Although Lucilla Poston and Lucy Chappell agree that this study is “timely and welcome”, it fails to provide the necessary evidence required for the National Institute for Health and Clinical Excellence (NICE) to re-evaluate the guidelines for weight management during pregnancy. Poston and Chappell refer to various ongoing trials that will provide a greater understanding of effective interventions in pregnant overweight and obese women .

Written By Petra Rattue