Intrapartum fetal asphyxia: study of umbilical cord blood lactate in relation to fetal heart rate patterns

Purposes To correlate between umbilical artery cord blood lactate and acid-base status with intrapartum fetal heart rate monitoring, and to measure the reliability of umbilical cord blood lactate for prediction of early neonatal outcome. Methods Sixty-six participants with intrapartum abnormal fetal heart rate monitoring and 60 participants with normal intrapartum recordings were recruited. The abnormal recordings included late onset, atypical variable and simple variable decelerations. After delivery, the arterial cord blood lactate, pH, actual base excess (ABE), and Apgar score were measured in all participants. Results There was significant inverse correlation between cord lactate and pH and ABE in all participants (correlation coefficient = -0.7, p < 0.0001). The cord lactate was significantly higher in the late onset and atypical variable decelerations groups compared to control (p < 0.0001). There was no significant correlation between the Apgar score and blood lactate in all groups; however, the sensitivity and specificity of cord lactate to predict low score at 5 min were higher in comparison to cord pH. Conclusions Umbilical cord blood lactate is a reliable marker for intrapartum fetal asphyxia compared to cord acid-base status with better prediction for newborns with low Apgar score.