Fetal bradycardia induced by maternal exercise

Fetal bradycardia that occurred during maternal exercise (a symptom-limited VO2 max treadmill test) in the fetuses of three healthy pregnant women is described. The mechanism of this bradycardia is believed to be mediated by catecholamines. The fetal bradycardia seems to be transitory and appears to be compensated for by an increase in fetal heart rate after the cessation of exercise.