Analysis of heart rate patterns preceding fetal death

An analysis of fetal heart rate patterns preceding death is presented in 7 patients. The intrapartum deaths were not predictable on the basis of clinical evaluation. Predeath recording time varied from 11 minutes to 7.75 hours. An atypical deceleration pattern was observed in 3 patients terminally with associated loss of beat-to-beat variability. These occurred with uterine contractions, but had the characteristic appearance of variable decelerations (CC). This pattern was characterized by short contraction to deceleration intervals, and by large drops in the rate (62-102 beats/min). In 6 of the 7 patients, there was either absent (0-5 beats/min) or diminished (5-10 beats/min) beat-to-beat variability. In 1 the terminal recording showed an absolutely fixed rate with a progressive loss of beats and an increased amount of electrical noise.