Changes in fetal heart rate-uterine contraction patterns associated with eclampsia.

Eclamptic seizures have been associated with fetal bradycardia and rapid onset or progression of labor. The fetal heart rate (FHR)-uterine contraction patterns during 14 seizures in 10 eclamptic patients were studied. Some seizures occurred in patients in whom magnesium sulfate levels were in the therapeutic range. The FHR response during an eclamptic episode was generally prolonged bradycardia. Uterine activity was noted to increase during seizure activity and preceded the fall in FHR. As seizure activity subsided, uterine hyperactivity diminished and the FHR rose, frequently demonstrating compensatory tachycardia. The clinical implications and possible pathophysiologic mechanisms of the FHR-uterine contraction observations are discussed.