A randomized controlled trial of prenatal physical activity to prevent gestational diabetes: design and methods

Women diagnosed with gestational diabetes mellitus (GDM) are at substantially increased risk of developing type 2 diabetes and obesity, currently at epidemic rates in the United States. GDM, therefore, identifies a population of women at high risk of developing type 2 diabetes and provides an opportunity to intervene before the development of this disorder. It is well recognized that acute as well as chronic physical activity improves glucose tolerance in type 2 diabetes. To date, however, primary prevention trials have not been conducted to test whether an increase in physical activity reduces risk of developing GDM among women at high risk of this disorder.

The aims of this study are to investigate the effects of a motivationally targeted, individually tailored 12-week physical activity intervention on (1) development of GDM, (2) serum biomarkers associated with insulin resistance, and (3) the adoption and maintenance of exercise during pregnancy. Women at high risk of GDM are recruited in early pregnancy and randomized to either an individually tailored exercise intervention or a comparison health and wellness intervention.

The overall goal of the exercise intervention is to encourage pregnant women to achieve the American College of Obstetricians and Gynecologists guidelines for physical activity during pregnancy through increasing walking and developing a more active lifestyle.

The intervention takes into account the specific social, cultural, economic, and physical environmental challenges faced by pregnant women of diverse socioeconomic and ethnic backgrounds.