Fetal heart rate patterns and scalp blood pH as predictors of fetal distress.

Repeated samplings of scalp blood pH were obtained from 62 fetuses in whom continuous fetal heart rate monitoring was indicative of fetal distress. In all, 182 scalp blood samples were evaluated. Umbilical cord blood pH was determined immediately after delivery in 48 cases. In addition to heart rate abnormalities, fetal metabolic changes were considered in determining the mode of delivery. Vaginal delivery was allowed in 74.2% of the patient in our series and only 25.8% had cesarean sections. Repeated scalp blood pH sampling proved to be an important adjunct to continuous fetal heart rate monitoring in increasing the accuracy of diagnosis of fetal distress.