Routine measurements of umbilical artery lactate levels in the prediction of perinatal outcome.

Abstract

Our purpose was to compare lactate levels with acid-base balance in the umbilical artery with respect to the prediction of pregnancy outcome. A prospective study of 4045 cord samples was performed. Lactate was measured with a new method that requires 5 microliters of blood and provides the result within 1 minute. The umbilical artery lactate concentrations were significantly elevated in instrumental deliveries (2.65 +/- 1.2 mmol/L) and in emergency cesarean sections (2.44 +/- 1.7 mmol/L) compared with spontaneous vaginal delivery (1.87 +/- 0.94 mmol/L) (p < 0.001, p < 0.001). Lactate correlated significantly to fetal pH, hemoglobin, base deficit, PCO2, and HCO3-. Lactate was comparable to pH and base deficit in sensitivity, specificity, and positive and negative predictive values in relation to morbidity and mortality. Umbilical artery lactate concentration and acid-base balance predicted perinatal outcomes with similar efficacies; however, its simplicity makes lactate analysis an interesting alternative in obstetric care.