Understanding health behaviours in a cohort of pregnant women at risk of gestational diabetes mellitus: an observational study.

OBJECTIVE: To assess health behaviours, physical activity levels, weight gain and development of gestational diabetes mellitus (GDM) in high-risk women.
DESIGN: An observational sub-study of a larger randomised controlled trial.
SETTING: A large tertiary hospital in Australia. POPULATION: Ninety-seven women (mean age 31.7 ± 4.5 years; body mass index 30.3 ± 5.9 kg/m(2) ) at risk of developing GDM.
METHODS: Women were identified as at risk of GDM based on a validated screening tool. Baseline measures were completed at 12-15 weeks of gestation and repeated at 26-28 weeks of gestation. MAIN OUTCOME MEASURES: Anthropometric (weight and height) and physical activity assessment (Yamax pedometer and International physical activity questionnaire), questionnaires (self-efficacy) and GDM screening.
RESULTS: By 28 weeks of gestation, there was a high GDM prevalence of 26% using the recent International Association of Diabetes and Pregnancy Study Group criteria. Weight gain in overweight (body mass index 25-29.9 kg/m(2)) and obese (body mass index >30.0 kg/m(2)) women exceeded minimum total weight gain recommendations set by the Institute of Medicine (P < 0.01). Physical activity levels were low and declined during pregnancy (5437 ± 2951 steps/day to 4096 ± 2438 steps/day, respectively, P < 0.001). Despite reduced activity levels, increased weight gain and high GDM incidence many women did not accurately perceive GDM risk and were confident in their ability to control weight. A significant association with physical activity, weight and GDM outcome was not observed.
CONCLUSIONS: Overweight and obese pregnant women at risk for developing GDM demonstrate excessive weight gain and a reduced level of physical activity observed from early pregnancy to 28 weeks of gestation. Results highlight the need for targeted intervention in women at risk for developing GDM.