Background
Increasing physical activity in pregnancy may improve pregnancy outcomes for obese women. Exercise could reduce gestational weight gain, improve the maternal circulating lipid profile as well as alter leptin, Interleukin‐8 (IL‐8) and Monocyte Chemoattractant Protein‐1 (MCP‐1) levels.

Aim
The aim of this study was to investigate the effects of exercise on gestational weight gain, maternal circulating lipids, IL‐8, MCP‐1 and leptin levels in obese pregnant women.

Materials and Methods
The analysis was performed in the 35 obese women enrolled in the pilot BAMBINO randomised controlled trial who provided blood samples at 12‐ and 28‐weeks gestation. Women in the exercise intervention arm received an individualised exercise plan. Blood samples, exercise diary and pedometer data were obtained at 12‐, 20‐, 28‐ and 36‐weeks’ gestation. Cord blood was obtained at delivery.

Results
Women in the exercise arm exercised more than those in the control arm (P = 0.038). There was no difference in gestational weight gain, excess gestational weight gain, MCP‐1 and leptin levels between women in the exercise intervention (n = 19) or the control arm (n = 16). IL‐8 was not detectable. Exercise did not alter the maternal lipid profile.

Conclusions
The low level of physical activity achieved in obese women in the exercise intervention arm was insufficient to alter gestational weight gain, MCP‐1, leptin or circulating lipid levels.