Frequency: differs by race, estimates range from < 1% up to 2.5% of neonates
Clinical features:
(1) jaundice with unconjugated hyperbilirubinemia
(2) onset 7-10 days after delivery with peak at 2-3 weeks
(3) affected neonates are being breastfed
(4) The hyperbilirubinemia disappears if breastfeeding stopped for 24-48 hours during which formula is given.
(5) infants are otherwise healthy with other causes of jaundice excluded
(6) reinstitution of breastfeeding often does not result in recurrence of the jaundice
Theories for occurrence:
(1) polymorphism in UDP-glucuronosyltransferase (related to Crigler-Najjar or Gilbert's syndrome)
(2) steroid, long chain fatty acid or other compound in breast milk that interferes with glucuronyl transferase activity
(3) increased enterohepatic cycling of bilirubin
Differential diagnosis:
(1) hemolytic disease of the newborn
(2) transient neonatal hyperbilirubinemia
(2) hypothyroidism
(3) neonatal hepatitis or other liver disease
(4) Crigler-Najjar syndrome
(5) early onset feeding-related jaundice (previous section)
(6) congenital atresia of the bile ducts
