Objective: To analyze the relation between fetal acid-base and neonatal status in an observational cohort study of 900 consecutive women with singleton pregnancies at term undergoing elective cesarean section. Methods: The women were divided into 3 groups according to the type of anesthesia administered. Fetal acid-base status was assessed from umbilical cord blood (both artery and vein) and intermediate neonatal outcome was noted. Results: Epidural anesthesia was associated with the highest pH. The lowest pH and the highest pC02 values were associated with spinal anesthesia. Although maternal general anesthesia was associated with the highest values for partial pressure and saturation of oxygen in umbilical arterial blood, the newborns were more likely to be depressed than those born following spinal (P=0.0016) or epidural (P=0.0002) anesthesia. Conclusions: If fetal oxygenation is the goal, general anesthesia provides the highest values for partial pressure and saturation of oxygen in umbilical arterial blood. However, epidural anesthesia was associated with better fetal and neonatal status than either spinal or general anesthesia.