Exercise-related changes in umbilical and uterine artery waveforms as assessed by Doppler ultrasound scans

OBJECTIVE: The purpose of this study was to assess the effect of strenuous symptom-limited exercise on umbilical and uterine blood flow. STUDY DESIGN: Twenty-two primiparous women between 30 and 34 weeks of gestation were recruited. At rest, umbilical and uterine artery waveforms,were assessed by measuring the pulsatility index. This was followed by a symptom-limited incremental exercise test. Fetal umbilical and maternal uterine artery circulations were assessed after exercise. RESULTS: Strenuous maternal exercise was demonstrated by the significant change in physiologic parameters, which was associated with an immediate increase in fetal heart rate, a significant increase in the right uterine artery pulsatility index, and a reduction in the umbilical artery pulsatility index. CONCLUSION: The modest change in the uterine artery pulsatility index without an adverse change in the umbilical artery pulsatility index indicates that a single bout of maximum symptom-limited exercise does not have immediate adverse fetal or maternal cardiovascular effects.