NEONATAL JAUNDICE

Abstract

Jaundice is a common and mostly benign condition in neonates but because of the potential toxicity of bilirubin, neonates must be monitored to identify those who might develop severe hyperbilirubinemia and, in rare cases, acute bilirubin encephalopathy or kernicterus.

Over 60 percent of term and 80 percent of preterm babies develop clinical jaundice during the first week of life. Clinical jaundice, in neonates appears first on the face at a serum bilirubin concentration of 5 mg per dl in contrast to adults who appear jaundiced when the serum bilirubin is greater than 2 mg per dl.

The yellowish discoloration is usually the result of deposition of unconjugated, nonpolar, lipid soluble indirectly reacting bilirubin present in the skin formed from enzymatic and non enzymatic degradation of haemoglobin while a part of this discoloration can be attributed to deposition of the pigment after it has been converted in the liver by uridinediphosphoglucouronic acid (UDP)-glucuronyltransferase to the polar, water soluble direct reacting ester glucuronide of bilirubin. Severe untreated unconjugated hyperbilirubinemia is potentially neurotoxic and conjugated hyperbilirubinemia indicates a serious hepatic or systemic disease. In the present chapter, we would be mainly concentrating over unconjugated hyperbilirbinemia for all practical purposes.