Umbilical Cord Blood Lactate as a Predictor of Adverse Early Neonatal Outcome in Low-Risk Term Primigravidae: A Prospective Observational Study

Background: Intrapartum hypoxia remains an important cause of early neonatal morbidity, yet conventional intrapartum surveillance has a low positive predictive value for fetal acidaemia. Cord blood lactate, the direct end-product of anaerobic metabolism, is measurable on a handheld meter. We evaluated it as a predictor of adverse early neonatal outcome in low-risk term primigravidae. Methods: Prospective observational study of 150 low-risk primigravidae with singleton term vertex pregnancies in labour at a tertiary teaching hospital in south India. Cord blood (2 mL) was collected immediately after double clamping and lactate measured. Neonates were grouped as no (<5 mmol/L), mild (5–10 mmol/L) or severe (>10 mmol/L) acidaemia. Associations with Apgar scores, neonatal intensive care unit (NICU) admission, neonatal complications, cardiotocography (CTG) findings and maternal variables were tested by chi-square or Fisher exact tests; diagnostic accuracy was computed post hoc. Results: Severe acidaemia was present in 26 neonates (17.3%). It was commoner with non-reassuring 5-minute Apgar (80.0% versus 12.9%, p<0.001) and 1-minute Apgar (45.2% versus 10.1%, p<0.001), abnormal CTG (27.1% versus 8.8%, p=0.002), NICU admission (28.4% versus 8.4%, p=0.005) and neonatal complications (28.8% versus 9.9%, p=0.005). Lactate >10 mmol/L predicted a 5-minute Apgar score <7 with 80.0% sensitivity and 87.1% specificity; lactate <5 mmol/L had a negative predictive value of 100%. Cord lactate was not associated with maternal comorbidity or amniotic fluid index (all p>0.05). Conclusion: Umbilical cord blood lactate correlates with early neonatal outcome and identifies at-risk neonates, including some with reassuring Apgar scores. It is an inexpensive, practical adjunct to conventional intrapartum assessment.