Revisiting ABO incompatibility as a risk factor for significant neonatal hyperbilirubinemia

Babies with ABO incompatibility are often advised frequent biochemical screening and prolonged hospital stay. Our primary objective of the study was to compare serum bilirubin levels at 48 h and 96 h of age in neonates with and without ABO incompatibility. Our prospective study included neonates with gestation ≥ 34 weeks, with or without ABO incompatibility (92 in each group). A direct Coombs test was performed on cord blood. The mean serum bilirubin and haematocrit levels in both groups at 48 h and 96 h were comparable. The mean reticulocyte count of babies with ABO incompatibility was, however, significantly higher. Late preterm and term neonates with and without ABO incompatibility have similar bilirubin levels and no increased risk of significant hyperbilirubinemia. Prolonged hospitalisation of these neonates appears to be unnecessary.