Jaundice is an important problem in the first week of life. It is a cause of concern for the physician and a source of anxiety for the parents. High bilirubin levels may be toxic to the developing central nervous system and may cause neurological impairment even in term newborns. Nearly 60% of term newborn becomes visibly jaundiced in the first week of life. In most cases, it is benign and no intervention is required. Approximately 5-10 % of them have clinically significant hyperbilirubinemia mandating the use of phototherapy.

Physiological jaundice
Jaundice attributable to physiological immaturity of neonates to handle increased bilirubin production. Visible jaundice usually appears between 24-72 hours of age. Total serum bilirubin (TSB) level usually rises in full-term infants to a peak of 6 to 8 mg/dL by 3 days of age and then falls. A rise to 12mg/dL is in the physiologic range. In premature infants, the peak may be 10 to 12 mg/dL on the fifth day of life, possibly rising over 15 mg/dL without any specific abnormality of bilirubin metabolism. Levels under 2mg/dL may not be seen until one month of age in both full term and premature infants. 4 Safe bilirubin levels
in preterms vary according to gestational age.

Pathological jaundice
TSB concentrations have been defined as non-physiologic if concentration exceeds 5 mg/dL on first day of life in term neonate, 10 mg/dL on second day, or 12-13 thereafter. Any TSB elevation exceeding 17 mg/dL should be presumed pathologic and warrants investigation for a cause and possible intervention, such as phototherapy. Appearance of jaundice within 24 hours, peak TSB levels above the expected normal range.

Phototherapy should be instituted when the total serum bilirubin level is at or above 15 mg/dL. Few term newborns with hyperbilirubinemia have serious underlying pathology. Jaundice is considered pathologic if it presents within the first 24 hours after birth, the total serum bilirubin level rises by more than 5 mg/dL per day or is higher than 17 mg/dL, or an infant has signs and symptoms suggestive of serious illness