Those with primarily elevated direct bilirubin. Direct
bilirubin >15% of total and therefore conjugated by the liver.
Infections including sepsis, perinatally acquired viral infections including
hepatitis, and intrauterine viral infections (hepatitis B, TORCHS).
Metabolic abnormalities including Rotor syndrome and
Anatomic abnormalities including biliary atresia and
obstructions as with a choledochal cyst.
Cholestasis from CVN/TPN antibiotics (especially
Galactosemia, tyrosinosis, cystic fibrosis, hereditary
Those with primarily elevated indirect bilirubin. Therefore not conjugated by liver. Two basic mechanisms:
From increased production of bilirubin (therefore hemolysis or hematoma
With positive direct Coombs' test (mother's antibodies on child's cells). Isoimmunization (Rh, ABO, minor blood group), erythroblastosis
With negative Coombs' test and RBC morphologic abnormalities.
Spherocytosis, thalassemias, G6PD deficiency, elliptocytosis, etc.
Extravascular blood. Cephalohematoma,
severe bruising, cerebral and pulmonary hemorrhage.
DIC, other hemolytic anemia
Polycythemia resulting from delayed clamping of cord, twin-twin transfusion,
From delayed excretion of bilirubin.
Inherited disorders of bilirubin metabolism including
Crigler-Najjar syndrome, Gilbert's disease, Dubin-Johnson syndrome, Rotor
Hypothyroidism and prematurity.