Early hospital discharge has increased the risk of severe jaundice in term neonates with ABO incompatibility and hemolytic disease.
Aims: a) To identify predictive factors of severe hyperbilirubinemia (requiring phototherapy) in the first week of life; b) to determine the serum unconjugated bilirubin (UB) level cutoff at 24-36 hours that better predicts severe hyperbilirubinemia.
Method: After parental consent was obtained, lab tests were measured at 24-36 hours, 3rd, 4-5th, 6-7th days of life. Predictive capacity of the serum UB level was assessed through the ROC curve analysis and estimation of the sensitivity, specificity and positive and negative predictive values of different serum UB level cut-offs.
Results: ABO incompatibility was identified in 172 (13.6%) of 1.263 healthy term newborns; 126 babies were included, 28 of them (22%) developed severe hyperbilirubinemia; 46 were excluded (33 did not grant consent, 11 were lost to follow up and 2 received NICU's care). These last had higher UB level at 24-36 hours than those that did not develop the condition during the first week of life. A serum UB value of 8.75 mg% at 24-36 hours showed the best performance: sensitivity 78%, specificity 83%, positive predicted value 45% and negative 95%.
Conclusions: Serum UB at 24-36 hours of life might contribute to identify those term newborns with ABO incompatibility that have the highest risk of developing severe jaundice.