Neonatal Hyperbilirubinemia (Jaundice), continued
Evaluation of Hyperbilirubinemia
With a serum bilirubin level of around 5 mg/dl, jaundice appears on the face. Jaundice proceeds caudally as the bilirubin level increases. The physical examination should be performed looking for extravascular collections of blood such as a cephalohematoma or for hepatosplenomegaly which is found in infection and hemolytic anemia. Petechiae suggest intrauterine infection, sepsis, or severe hemolytic disease. Lethargy, poor feeding, and temperature instability may indicate sepsis.
The following initial laboratory studies should be obtained in any infant who appears to have pathological jaundice:
- Serum total and conjugated bilirubin level.
- CBC and reticulocyte count (a low hemoglobin level suggests hemolysis; leukopenia, with or without thrombocytopenia, is indicative of infection; the blood film might show spherocytes, as seen in congenital spherocytosis; a reticulocyte count of more than 6% suggests hemolysis).
- Blood type and Rh on the mother and baby will point to Rh or ABO incompatibility.
- Direct Coombs test on the baby, if positive, suggests Rh or ABO incompatibility.
