The Feasibility of Adding Fetal Heart Rate to the Nocturnal Polysomnogram

Abstract

To demonstrate that fetal heart rate measured by ultrasound can be successfully captured and monitored throughout the nocturnal polysomnogram. Fetal heart rate by ultrasound using an abdominal belt (Hewlett Packard Fetal Monitor 8040A) was measured during 1 overnight polysomnogram in volunteers in late pregnancy and added to a digitized polysomnography system (Alice 4, Respironics). In 6 women with a single fetus in their third trimester, the fetal heart rate monitor band only infrequently needed to be readjusted. Fetal kicks and movements resulted in signal loss, usually with subsequent recapture without having to awaken the mother. Fetal heart rate, 1 of the classic signals of fetal distress, can be added to the nocturnal polysomnogram with minimal disruption of maternal sleep and with signal capture throughout the night.