To the Editor:—Dr. Diamond's program for the prevention of kernicterus by the use of replacement transfusion in patients with hemolytic disease of the newborn has been satisfactorily established. The problem of hyperbilirubinemia due to slow maturation of the enzyme glucuronyl transferase, however, has not been critically studied in the normal newborn premature infants, either by large-scale evaluation of this normal pattern of hyperbilirubinemia or by long-term comparison of neonatal bilirubinemia with ultimate neurological development. The report of this series is the beginning of our attempt to study patients in this fashion.
In response to Dr. Thelander, we entirely agree with him. Drs. William Silverman and Jack Shiller, at the American Pediatric Society meeting in Swampscott, Massachusetts, in May 1960 gave a three-year report on the neurological development of these children, whose bilirubin levels we had studied during the first week of life. No difference was noted in the neurological