PROLONGED NEONATAL JAUNDICE DUE TO UNCONJ UGATED BILIRUBIN

Neonatal jaundice due to unconjugated bilirubin is common because of t he specific characteristics of the metabolism of bilirubin in neonates . Prolonged unconjugated hyperbilirubemia (PUCH) can be defined as an increase in serum levels of unconjugated bilirubin with clinical jaund ice lasting beyond the first ten days of life. Pathophysiologic mechan isms include increased bilirubin production (hemolysis, erythrocyte en zyme deficiencies), transiently inadequate uptake or conjugation of bi lirubin (breast milk jaundice, congenital hypothyroidism), and inherit ed defects in bilirubin conjugation (Gilbert's disease, Crigler-Najjar syndrome). The diagnosis of PUCH in a neonate rests primarily on phys ical findings (color of the urine and feces, size and consistency of t he liver), whether the baby is breast-or bottle-fed, the family histor y, and the presence or absence of evidence of hypothyroidism. A small number of simple investigations are sufficient (blood cell counts, ret iculocyte count, hemoglobin level, and serum level of unconjugated bil irubin).