Exercise in pregnancy and maternal cardiovascular changes

Objective: To evaluate whether regular aerobic exercise during pregnancy reduces the risk of hypertensive disorders of pregnancy and improves maternal cardiovascular adaptation. Methods: This was a secondary analysis of a randomized clinical trial including women with singleton gestation randomly assigned in a 1:1 ratio to an exercise group or a control group. The intervention consisted of a structured aerobic exercise program from the first trimester until 35 weeks. Echocardiographic examinations were offered between 37 and 38 weeks. The primary endpoint was the incidence of gestational hypertension. Secondary outcomes included preeclampsia and echocardiographic hemodynamic, geometric and mitral inflow indices. Results: Among 938 randomized participants, 54 underwent echocardiography. The incidence of gestational hypertension was lower in the exercise group compared with the control group (10.1% vs 15.1%; RR 0.56, 95% CI 0.33–0.97). Preeclampsia incidence was 2.5% and 3.5%, respectively (RR 0.71, 95% CI 0.23–2.21). In the echocardiography subgroup, exercise participants had lower systolic and diastolic blood pressure, higher stroke volume (79.7 ± 7.3 vs 74.5 ± 9.2; p = 0.02), and more favorable mitral inflow indices, including a higher E’/A’ ratio (1.29 ± 0.17 vs. 1.15 ± 0.23; p = 0.01) and reduced impaired diastolic relaxation (0% vs. 27.3%; p < 0.01). Conclusion: Regular exercise during pregnancy is associated with lower risk of gestational hypertension and improved cardiovascular adaptation, supporting its role in maternal hemodynamic health. Trial registration: Clinicaltrials.gov NCT06355375 (Registration Date 20240409).