Abnormal fetal heart rate patterns during the active phase of labor: the value of fetal oxygen saturation

Abstract

Objective: To determine the predictive value of intrapartum fetal oxygen saturation (SO2) for prediction of an umbilical artery pH less than 7.15 at birth in labors complicated by abnormal fetal heart rate traces.

Study design: Eighty-five primigravidas in spontaneous labor complicated by abnormal fetal heart rate traces underwent fetal SO2 monitoring using the fetal pulse oximetry technique. Cases with an SO2 of < 30% were delivered by Cesarean section. Umbilical artery pH was measured at birth in all women.

Results: With the value set of 30% as the cut-off point of fetal oxygen saturation, the positive predictive value for umbilical artery pH of < 7.15 was 61.5% and the negative predictive value was 95.8%, with a sensitivity of 72% and a specificity of 93%.

Conclusions: Fetal pulse oximetry is a promising technique for assessment of fetal well-being during labor and may decrease the number of unnecessary Cesarean sections.