Fetal tachycardia can occur with maternal fever (hyperthermia); therefore, a low maternal temperature (hypothermia) might produce fetal bradycardia.
Five cases of fetal bradycardia are presented in gestations complicated by maternal hypothermia. The fetal heart rate (FHR) tracings demonstrated stable baselines of 88–96 beats per minute with moderate variability and accelerations. All baselines returned to normal after maternal warming measures.
A possible cause for fetal bradycardia with a stable baseline and moderate variability is maternal hypothermia, a pattern not indicative of fetal hypoxia. Delivery is not indicated, and maternal warming results in FHR baseline normalization.