The Impact of Antenatal Exercise in Overweight and Obese Women on Maternal and Offspring Health

Abstract

Background Overweight and obesity in pregnancy is associated with adverse health outcomes in both the mother and the offspring. It is not well established whether antenatal exercise can improve these outcomes. Hypothesis We hypothesized that antenatal exercise in overweight and obese women could improve offspring and maternal health and metabolic milieu, and protect offspring from adverse programming effects. Methods/Design A parallel two-arm randomised controlled trial was conducted in healthy non-smoking overweight and obese women (BMI≥25kg/m2) with a singleton pregnancy. Participants were randomised at 20 weeks of gestation to an intervention group (who underwent a home-based, moderate-intensity stationary cycling programme) or a control group (no exercise intervention). The primary trial outcome was birth weight and secondary outcomes included perinatal complications, neonatal body composition, maternal physical health (weight gain, fitness and body composition), quality of life, and pregnancy and delivery complications. Maternal and offspring (cord) blood metabolic markers were also measured. Primary analysis was based on intention-to-treat, using analysis of covariance regression models to evaluate differences between intervention and control groups, adjusting for pre-specified covariates. Results Seventy-five enrolled participants were randomised to intervention (n=38) or control (n=37) groups. Offspring birth weight was similar between groups (adjusted mean difference 104 grams, 95% CI -116 to 324, p=0.35). Maternal aerobic fitness improved following the intervention but there were no differences in maternal weight gain, quality of life, pregnancy outcomes, or postnatal maternal body composition between groups. Exercise compliance ranged from 0-85 % (mean 33%). Offspring neonatal adiposity and perinatal outcomes were similar. There was an increase in bone mineral content in offspring in the intervention group, and male offspring had increased adiposity compared to gender-matched controls. There were no differences in maternal metabolic markers between groups. Offspring in the intervention group had lower cord blood interleukin-6 levels, and male offspring also had reduced insulin-like growth factor binding protein-1 levels, while other markers were similar between groups. Conclusions These study finding suggest that non-weight-bearing antenatal exercise does not appear to improve short term maternal and offspring outcomes. However, improvement in maternal fitness and differences in offspring body composition and metabolic markers indicate the potential for long-term health effects. This needs to be established by further research.