University of Birmingham

Pregnant women may be better supported by trained dietitians to control weight gain during pregnancy, a new analysis of almost 100 studies shows.

The meta-analysis of almost 35,000 participants across 99 studies published in JAMA Network Open found that interventions from allied health professionals such as dietitians were the most beneficial for controlling gestational weight gain (GWG).

Spanning 30 years of international evidence, the research team including maternal health expert Professor Shakila Thangaratinam from the University of Birmingham identified that between 6 and 20 sessions on a one-to-one basis were most effective. Those sessions need to consider practical elements of pregnancy including nausea which may affect food and vegetable consumption, as well as cravings and fatigue.

The team also found less evidence for the exercise component of weight management during pregnancy and plans to manage weight gain that include exercise need to be carried out over a longer period of time over 20 weeks.

Professor Shakila Thangaratinam, Dame Hilda Lloyd Chair of Maternal and Perinatal Health at the University of Birmingham and co-author of the paper said:

“Weight gain during pregnancy is a normal process but the old adage that expectant mums are ‘eating for two’ and don’t need to worry about weight gain can lead to health consequences for mum and baby. We know that excessive gestational weight gain increasing the risks of the development diabetes and other complications.

“This study set about to encapsulate 30 years of evidence on what works well and not, and we found that experts in their fields such as dietitians were most effective at supporting healthy weight gain. Other interventions were also found to have some success but need to be started soon into the journey of pregnancy.”

Cheryce L. Harrison, BBNSc, PhD, senior research fellow and co-lead of the Healthy Lifestyle Stream at the Monash Centre for Health Research and Implementation at the School of Public Health and Preventive Medicine, Monash University in Melbourne, Australia, and colleagues said:

“In a secondary analysis of our 2022 systematic review reporting on the association of lifestyle interventions with efficacy in optimizing gestational weight gain, this meta-analysis aims to elucidate and describe components of antenatal lifestyle interventions that are associated with optimized gestational weight gain within published randomized clinical trials, providing critical and pragmatic information for implementations of trials in antenatal care settings.”