Jaundice is a common sign in the first 2 weeks of life. It is usually ‘physiological’, in that it is due to the functional immaturity of the normal liver, which matures rapidly after birth. Deep jaundice or the development of jaundice within 24 h of birth implies that additional factors such as haemolysis, infection or inborn metabolic errors may be present, and demands urgent investigation and treatment. An unconjugated bilirubin level above 300 μmol/l (or 250 μmol/l in premature infants) may damage the brain (kernicterus).

Jaundice that appears later than, or persists into, the third week of life is not likely to be benign ‘physiological’ jaundice and should be treated as requiring urgent investigation, as rapid diagnosis and prompt treatment may prevent death or permanent damage to the infant (Table 17.1). Jaundice at this stage, accompanied by pale grey (acholic) stools, dark urine and an elevated serum bilirubin which is largely conjugated bilirubin, may have a ‘surgical’ cause. Biliary atresia (or less commonly a choledochal cyst) causes an obstructive jaundice in the first months of life (Fig. 17.1). Severe hepatic damage associated with cholestasis may show a similar clinical picture. Neonatal hepatitis of unknown cause or hepatic damage secondary to septicaemia, viral infections (e.g. cytomegalovirus) or inborn errors of metabolism (e.g. galactosaemia) also needs to be considered. Jaundice without obstructive features (i.e. normal stool and urine colour) may follow less severe hepatic injury without cholestasis or be due to impaired bilirubin uptake and conjugation (e.g. hypothyroidism, haemolysis, breast milk jaundice or rare congenital enzyme defects).