In the March issue of the American Journal of Diseases of Children, eight cases of neonatal hyperbilirubinemia associated with breast feeding are reported.1 This syndrome is characterized by prolonged unconjugated (indirect-reacting) hyperbilirubinemia in an otherwise healthy breast-fed infant. It usually occurs in the second to fourth week of life and may last as long as eight weeks if breast feeding is continued. The hyperbilirubinemia may be marked; in one instance the bilirubin value was 29.8 mg/100 ml on the seventh day of life. Attempts to establish other causes for the jaundice were unsuccessful. Within 48 hours after cessation of breast feeding, however, the bilirubin level began to fall. With resumption of breast feeding, there is a decline in the rate of fall or even a second rise in bilirubin, but marked hyperbilirubinemia does not recur.
Arias et al2 made the original observation in 1964 and demonstrated that breast