Routine measurements of cord arterial blood lactate levels in infants delivering at term and prediction of neonatal outcome

ABSTRACT

Objective: Our purpose was to evaluate the relationship between umbilical cord arterial blood lactate levels with acid base balance to the mode of delivery and short-term neonatal outcome in a large multiracial population delivering at term in University of Malaya Medical Centre. Materials and methods: Two thousand two hundred and twelve patients of more than 37 weeks of gestation with singleton, liveborn infants with no major anomalies delivering between January 2013 to December 2013 were analysed. Lactate was measured by using portable Lactate analyzer that requires 5 µml of blood and provides the result within 1 minute. The deliveries took place at the Department of Obstetrics and Gynaecology, University Malaya Medical Centre, Malaysia where umbilical cord blood sampling and blood gas analysis is a part of the routine assessment of all newborn. Results: Gestational age ranged from 37 to 43 weeks (mean 39.05 weeks). The highest mean arterial cord lactate values were noted among babies delivered instrumentally (4.87 mmol/L). Infants who had a normal vaginal delivery had the second highest levels (3.36 mmol/L), followed by infants delivered by emergency caesarean section (3.30mmol/L). The lowest lactate values were noted in deliveries by elective caesarean section (3.0mmol/L). Cord arterial lactate levels were significantly higher among infants born with low Apgar scores (7.02 mmol/L vs 4.6mmol/L, P < 0.001). High arterial cord lactate was a significant predictor of admission to Neonatal intensive care unit (NICU) was 6.0mmol/L. Receiver operator curve (ROC) analysis suggests that lactate and pH are virtually equivalent in their correlation with adverse neonatal outcome. Conclusion: Cord lactate levels are significantly related to the mode of delivery and is equivalent to cord arterial pH in predicting adverse neonatal outcomes, with similar efficacies; however, its simplicity, less sampling failure and low cost makes lactate analysis an interesting alternative in obstetric care.