Intrapartum fetal heart rate monitoring. IV. Observations on elective and nonelective fetal heart rate monitoring.

Heart rate tracings and outcome in 919 electively and 1,077 nonelectively monitored fetuses were compared in order to investigate the value of elective surveillance of the fetal heart rate (FHR) in either group. A threefold higher perinatal mortality and a twofold higher number of low 5-minute Apgar scores were observed among patients with risk factors compared to electively monitored pregnancies. In the beginning of monitored labor, fetuses with risk factors exhibited a higher incidence of FHR patterns with low FHR variability than fetuses without risk factors. In the final phase of labor, FHR patterns indicative of hypoxia, i.e., late decelerations and severe and atypical variable decelerations, were found more often in the nonelective than in the elective group. Umbilical cord problems reflected by the occurrence of variable deceleration were responsible for the majority of low Apgar scores observed among electively monitored fetuses. The findings and their implications for FHR monitoring are discussed.