Prenatal Exercise and Cardiorespiratory Health and Fitness: A Meta-analysis

PURPOSE: To examine the influence of prenatal exercise on maternal cardiorespiratory health and fitness during pregnancy. METHODS: Online databases were searched up to February 25, 2019. Studies of randomized controlled trials (RCTs) were eligible, which contained information on the relevant population (pregnant women), intervention (subjective or objective measures of frequency, intensity, duration, volume, or type of exercise), comparator (no exercise intervention), and outcomes (maternal cardiorespiratory fitness [CRF], including VO2max, submaximal VO2, VO2 at anaerobic threshold, and cardiorespiratory health, including resting heart rate, resting systolic and diastolic blood pressure during pregnancy). RESULTS: From 2699 unique citations, 26 RCTs (N= 2292 women) were included. Of these, one study reported measured VO2max, seven reported predicted VO2max, three reported submaximal VO2, and two studies reported VO2AT."Low" to "high" certainty evidence revealed that exercise was associated with improved predicted/measured VO2 max (five RCTs, n=430; mean difference [MD]=2.77 mL/kg/min; 95% confidence interval [CI]: 0.32 to 5.21, I=69%), reduced resting heart rate (nine RCTs, n=637; MD= -1.71 bpm; 95% CI: -3.24 to -0.19, I=13%), resting systolic blood pressure (16 RCTs, n=1672; MD: -2.11 mmHg, 95% CI: -3.71 to -0.51, I=69%) and diastolic blood pressure (15 RCTs, n=1624; MD: -1.77 mmHg, 95% CI: -2.90 to -0.64, I=60%). CONCLUSION: Prenatal exercise interventions improve maternal predicted/measured VO2max and reduce resting heart rate and blood pressure. This review highlights the need for additional high-quality studies of CRF (namely VO2max and VO2 peak) in pregnancy.PROSPERO registration number: CRD42019131249.