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.