Regular maternal exercise dose and fetal heart outcome.

Area of Science:

• Obstetrics and Gynecology
• Fetal Physiology
• Maternal Health

Background:

• Previous research indicated lower fetal heart rate (HR) and increased HR variability (HRV) in exercising pregnant women, mirroring adult training responses.
• Dose-response relationships between physical activity and cardiorespiratory fitness are established in adults.

Purpose of the Study:

• To investigate a potential dose-response relationship between maternal physical activity and fetal HR, HRV, and sympathovagal balance.
• To determine if maternal exercise habits during pregnancy impact fetal cardiovascular regulation.

Main Methods:

• Pregnant women (n=50) completed physical activity questionnaires detailing duration, intensity, and frequency.
• Magnetocardiogram recordings assessed fetal HR, HRV, and sympathovagal balance at 36 weeks gestation.
• Spearman correlations and regression analyses examined associations, controlling for covariates.

Main Results:

• Maternal physical activity intensity negatively correlated with fetal HR in the active state (P < 0.05).
• Third-trimester physical activity duration positively correlated with fetal HRV (P < 0.05).
• No significant associations were found between maternal activity and fetal sympathovagal balance.

Conclusions:

• Maternal physical activity dose in the third trimester is associated with fetal heart adaptations resembling a trained response.
• These findings suggest potential health benefits of maternal exercise on fetal cardiovascular development, warranting further investigation.