Prediction of Respiratory Morbidities in Late Preterm Neonates Using Cord Blood Arterial Lactate and Base Excess

Background: Late preterm neonates may have the external appearance and behavior similar to their counterparts. However, they are susceptible to various neonatal morbidities , due to their physiological and metabolical immaturity. To assess the correlation between cord blood arterial lactate levels and base excess with the development of respiratory distress in late preterm neonates. Methods: All inborn neonates born at Kasturba hospital Manipal, satisfying the criteria of late preterm infants (34-36 6/7 weeks) were included in this prospective observational study.The data recorded included gender, birth weight, multiple births, presence of major congenital anomalies, mode of delivery, APGAR score at minute 5, need for resuscitation, admission to the neonatal intensive care unit (NICU), and days of hospitalization. Lactate and base excess were estimated using blood obtained from umbilical artery sampling. The primary outcome assessed was the requirement of delivery room resuscitation. The secondary outcomes assessed were the development of respiratory distress, requirement of invasive/non- invasive ventilation, and respiratory support. Results: Cord blood base excess levels were significantly higher in late preterm neonates requiring delivery room resuscitation compared to those who did not require resuscitation (median: -8 vs -4mEq/L, p-value: 0.002),In terms of respiratory morbidities, cord blood base excess levels were significantly higher in neonates with respiratory distress syndrome (RDS)(median: -8.5 vs -3.4 mEq/L, p-value 0.001), and transient tachypnea of newborn (TTNB) (median: -8 vs -3.4 mEq/L, p-value 0.004), compared to those without RDS and TTNB.However,there was no significant association between cord blood lactate levels and the outcomes assessed. Conclusion: Estimation of arterial base excess levels obtained from umbilical cord blood sampling during delivery may serve as a sensitive marker for predicting respiratory morbidities in late preterm neonates.