The Treatment of Obese Pregnant Women (TOP) study: A randomized controlled trial of the effect of physical activity intervention assessed by pedometer with or without dietary intervention in obese pregnant women

Objective The objective of the study was to assess physical activity intervention assessed by a pedometer with or without dietary intervention on gestational weight gain (GWG) in obese pregnant women by comparing with a control group. Study Design This study was a randomized controlled trial of 425 obese pregnant women comparing 3 groups: (1) PA plus D, physical activity and dietary intervention (n = 142); (2) PA, physical activity intervention (n = 142); and (3) C, a control group receiving standard care (n = 141). All participants routinely in gestational weeks 11-14 had an initial dietary counseling session and were advised to limit GWG to less than 5 kg. Physical activity intervention included encouragement to increase physical activity, aiming at a daily step count of 11,000, monitored by pedometer assessment on 7 consecutive days every 4 weeks. Dietary intervention included follow-up on a hypocaloric Mediterranean-style diet. Instruction was given by a dietician every 2 weeks. The primary outcome measure was GWG, and the secondary outcome measures were complications of pregnancy and delivery and neonatal outcome. Results The study was completed by 389 patients (92%). Median values of GWG (ranges) were lower in each of the intervention groups (PA plus D, 8.6 [-9.6 to 34.1] kg, and group PA, 9.4 [-3.4 to 28.2] kg) compared with the control group (10.9 [-4.4 to 28.7] kg [PA+D vs C]; P =.01; PA vs C; P =.042). No significant difference was found between the 2 intervention groups. In a multivariate analysis, physical activity intervention decreased GWG by a mean of 1.38 kg (P =.040). The Institute of Medicine's recommendations for GWG were more frequently followed in the intervention groups. Conclusion Physical activity intervention assessed by pedometer with or without dietary follow-up reduced GWG compared with controls in obese pregnant women.