Correlation of cord blood bilirubin and neonatal hyperbilirubinemia in the setting of ABO incompatibility

Abstract

Background: Neonatal hyperbilirubinemia (NHB) is the most common clinical condition requiring evaluation and treatment in neonates. Umbilical cord bilirubin measurement is a cheap, readily available, non-invasive procedure which helps in predicting the developing of hyperbilirubinemia in newborns. The aim of the study was to determine the correlation between cord blood bilirubin and subsequent development of clinically significant NHB in ABO incompatibility at 24 hours of life.Methods: 120 healthy term inborn neonates with A, B or AB blood group born to healthy mothers with O blood group were enrolled in this prospective clinical study, during the study period of 12 months, from June 2020 till May 2021. Cord blood (2 ml) was collected from placental side of cord and blood group and total and direct serum bilirubin were estimated. Venous blood (2 ml) sample was collected from peripheral vein of the baby and total and direct serum bilirubin estimation was done at 24, 48 and 72 hours of life.Results: During the study period, incidence of significant hyperbilirubinemia at 24 hours of age was 21.6%. Using cord bilirubin level of ≥3.5 mg/dl, hyperbilirubinemia can be predicted with sensitivity of 38.4%, specificity of 90.4% and positive predictive value of 52.6% and negative predictive value of 84.1%. Cord bilirubin and 24 hours postnatal serum bilirubin showed a positive correlation in this study.Conclusions: From the results and observations of the present study, one can consider the umbilical cord blood to be an important predictor for the occurrence of significant hyperbilirubinemia in newborns subsequently.