Are Cord Blood Bilirubin Values Trustable to Predict the Forthcoming Significant Hyperbilirubinemia Requiring Treatment in Healthy Term Newborns?

Abstract

Background: Jaundice is a clinical condition that is often observed in pediatric practice and constitutes one of the major issues within the neonatal period. As severe jaundice causes neurotoxicity (kernicterus), the diagnosis and treatment of severe hyperbilirubinemia is very important. Early prediction will help in early discharge and will prevent hospitalization of babies and mothers. On the other hand, predicting outcome in high risk neonates for subsequent hyperbilirubinemia is required. Objectives: This study investigates the predictive value of umbilical cord serum bilirubin (UCSB) for subsequent hyperbilirubinemia which is a required treatment in healthy term newborns. Methods: In this prospective study, 238 healthy term newborns were inducted into the study. Soon after delivery, the cord blood was sent for serum bilirubin analysis. Newborns were followed up by TCB (transcutaneous bilirubinometry) until the third day post birth and those who showed significantly high TCB values, according to the hour-specific normogram, received the appropriate intervention and treatment. The data were analyzed using t-Test, ROC (receiver operating characteristic) curve, and chi-square tests. Results: Of 238 newborns, 27 (11.4%) cases developed hyperbilirubinemia (bilirubin ≥ 15 mg/dL), which required phototherapy. There were no significant differences between the cases who did and who did not develop hyperbilirubinemia (bilirubin < 15 mg/dL) with respect to various factors that might be associated with the risk of hyperbilirubinemia such as mode of delivery and gender. However, two groups were significantly different in terms of cord bilirubin levels. ROC (receiver operating characteristic) analysis showed that the critical value of umbilical cord serum bilirubin (UCSB) ≥ 2.25 mg/dl had high sensitivity (92.6%), good positive and negative predictive value (66% and 69% respectively). Conclusions: UCSB level ≥ 2.25 mg/dL can be a useful predictor of hyperbilirubinemia in healthy term newborns on the third day. Therefore, infants with UCSB level ≥ 2.25 mg/dL should be followed up strictly either in a hospital or in an outpatient department on the third day, whereas neonates with cord bilirubin level < 2.25 mg/dL are probably safe for early discharge.