The Relationship between the Lactate Level of Umbilical Cord Blood with Early Neonatal Complications

Most studies showed that low cord blood pH was associated with short-term mortality as well as long-term neurological disorders, but few studies showed associations between high cord blood lactate and adverse short-term outcomes. This study aimed to determine the association between umbilical cord blood lactate during the first hour of birth in infants with 5th-minute Apgar scores <7 and short-term neonatal complications.

In this cross-sectional study, 49 pregnant women over 37 weeks gestation referred to the maternity wards of Academic Hospitals of the Mashhad university of medical sciences with the onset of labor, whose neonates scored below 7 in 5th-minute Apgar, were included after obtaining informed consent, by convenient sampling method. Preliminary information was recorded. Also, a blood sample was taken from the umbilical artery and its pH, pCO2, bicarbonate, and lactate levels were measured. The neonatal outcomes and complications and outcomes (discharge or infant death) were evaluated.

Overall, 25 male (51.0%) and 24 female neonates (49.0%) with a mean gestational age of 39.3±1.1 weeks were studied. Cord blood lactate concentrations were significantly higher in neonates with hypoxic-ischemic encephalopathy, intubation-ventilation, hypothermia, meconial aspiration, NICU admission, and those who died compared with the opposite groups (P<0.05). The best lactate cut-off point for predicting hypoxic ischemic encephalopathy and intubation was 4.55mg/dl, while for predicting neonatal death it was 6.19mg/dl with 100% sensitivity and 97.4% specificity.

Umbilical cord blood lactate measurement can be a highly accurate measure of neonatal outcome and early complications that can greatly help with the health status assessments of infants with adverse Apgar scores at birth, their prognosis, and management.