Exercise Training In Pregnancy For Women With Bmi ≥ 28. A Randomized Controlled Trial.

Abstract

PURPOSE: Maternal obesity is a risk factor for adverse pregnancy outcomes, and excessive gestational weight gain (GWG) is further increasing the risk. Previous lifestyles interventions during pregnancy have shown conflicting results, and have often combined effects of physical activity with dietary guidance. Our aim was to assess the effects of regular exercise training during pregnancy on gestational weight gain (GWG) and incidence of gestational diabetes mellitus (GDM) in women with pre-pregnancy body mass index (BMI) of 28 kg/m2 or more. METHODS: This was a randomized controlled trial, which included women with a pre-pregnancy BMI (kg/m2) ≥ 28. Baseline testing and randomization to exercise or control were done in gestational week 12-18. We measured weight at baseline and at birth, GDM at baseline and gestational week 36 (late pregnancy). GDM was defined by a fasting oral 75 g glucose tolerance test ≥ 6,9 mmol/L and/or 2 hours ≥ 7,8 mmol/L. The exercise was supervised, 3 times per week; 35 minutes of moderate treadmill walking/running and 25 minutes of resistance training for large muscle groups. The control group received standard maternity care. Statistical analyses were done on basis of «intention to treat», with use of linear mixed model and mixed-effect logistic regression. RESULTS: 91 participants were randomized; 46 to exercise and 45 to control. 18 women were lost to follow up (8 exercise, 10 control). 47,7 % in the exercise group performed the training per protocol. At baseline mean weight in the exercise group was 95,5 ± 12,3 kg (BMI 33,9 ± 3,8 kg/m2), in the control group 98,3 ± 14,2 kg (BMI 35,2 ± 4,4 kg/m2). There was no difference in GWG between the exercise and control group (98,3 10,2 ± 5,2 kg and 9,36 ± 7,5 kg, respectively, p = 0.84). At baseline, 3 women in each group had GDM, whereas 2 women in exercise and 8 women in the control group had GDM in late pregnancy (p = 0.086). 2 of the women with GDM at baseline did not fulfill the criteria for GDM at late pregnancy. CONCLUSIONS: Regular exercise during the pregnancy among overweight/obese women did not reduce GWG, compared to a non-exercising control group. The women in the training group had a tendency of lower incidence of GDM in late pregnancy.