Neonatal Depression and Fetal Heart Rate Patterns During Labor

Abstract

Intrauterine pressure and fetal heart rate were monitored continuously in 84 patients in labor. The pH of fetal scalp and cord vein blood samples was determined in 41 of these patients. A regular heart rate during the entire course of monitoring was the exception rather than the rule. A regular fetal heart rate, deceleration alone and deceleration interspersed with accelerations during labor were associated with the delivery of both depressed and normal newborn infants. Umbilical cord entanglement may be diagnosed before birth by the frequency of variable decelerations during the course of labor. Fetal heart rate acceleration during contraction, without other changes, was an auspicious sign, except when the increase in rate exceeded 50 beats/min. Prolonged tachycardia was related to neonatal depression and fetal acidosis when it was associated with a deceleration rate of >50 beats/min. In 4 cases of cord prolapse, a distinct and readily recognized pattern of biphasic deceleration was noted.