Cardiovascular effects of exercise training in pregnant people with a high body mass index: secondary results from a randomised controlled trial (ETIP)

Abstract

Objectives We aimed to determine the effectiveness of exercise training during pregnancy on peak oxygen uptake (V̇ O2peak), cardiac function and flow-mediated dilatation (FMD) of the brachial artery throughout pregnancy and post partum in individuals with a prepregnancy body mass index (BMI) ≥28 kg/m2. Trial design Parallel-group randomised controlled trial (RCT). Methods The exercise group in the Exercise Training in Pregnancy (ETIP) RCT was offered 3 weekly supervised exercise sessions comprising 35 min of moderate-intensity treadmill walking followed by 25 min of strength exercises. The intervention started in gestational weeks 12–18 and continued throughout pregnancy. We measured V̇ O2peak and FMD at baseline, in gestational weeks 34–37 and 3 months post partum and offered echocardiography in gestational weeks 14, 20, and 32, and 6–8 weeks postpartum. Results Of the 91 participants included in ETIP, 87 participants (age: 31.3±4.2 years, BMI: 34.6±4.3 kg/m2) provided data on V̇ O2peak, cardiac function and/or FMD. There was no statistically significant effect of exercise training on V̇ O2peak in gestational weeks 34–37, with an estimated effect of 1.7 mL/min/kg (95% CI −0.4 to 3.7, p=0.112) or post partum (1.6 mL/min/kg, 95% CI −0.2 to 3.4, p=0.079), compared with the control group. There were no statistically significant between-group differences in either FMD or any of the echocardiographic outcomes. Only 50% of the participants in the exercise group fulfilled our prespecified adherence criteria. Conclusion Offering pregnant individuals with BMI ≥28 kg/m2, a supervised exercise intervention did not improve cardiorespiratory fitness, cardiac function or FMD.