In this week's PLoS Medicine, Riitta Luoto and colleagues from the UKK Institute for Health Promotion Research, and University of Tampere, Finland, evaluate whether lifestyle interventions can reduce the risk of high birthweight babies and gestational diabetes amongst pregnant women at high risk for these outcomes.

They report the results of a cluster randomized trial in which groups of maternity clinics in 14 municipalities in Finland were randomized to an intervention.

The intervention comprised physical activity and dietary counselling, and was compared with a control arm in which usual care was offered.

The researchers find that babies born to women in the intervention arm had a roughly 44% reduced risk of being large for gestational age. However, they failed to show that the resulted in a reduced risk of gestational diabetes in women participating in the trial.

The authors comment that "The findings of our study emphasize counseling on the topics of physical activity, diet, and weight gain in especially for women at risk for in order to prevent large for gestational age newborns possibly causing problems in delivery, and both the mother's and the child's later weight development".

More information: Luoto R, Kinnunen TI, Aittasalo M, Kolu P, Raitanen J, et al. (2011) Primary Prevention of Gestational Diabetes Mellitus and Large-for-Gestational-Age Newborns by Lifestyle Counseling: A Cluster-Randomized Controlled Trial. PLoS Med 8(5): e1001036. doi:10.1371/journal.pmed.1001036