Arias icterus: Prolonged unconjugated hyperbilirubinemia caused by breast milk

Abstract

Breast milk jaundice occurs in 1-2% of healthy breast-fed newborns and young infants. It develops as the result of liver immaturity and the inhibitory effect of mother's milk to the clearance of unconjugated bilirubin. The paper analyzes variations in the level and length of unconjugated hyperbilirubinemia in breast-fed infants. The study was conducted on a sample of 29 young infants (19 male) with breast milk jaundice. All infants were born on time, by natural delivery and without complications. All were on breast-feeding only and developed optimally. None of the infants had either haemolysis or any other disease associated with unconjugated hyperbilirubinemia. All infants had physiological jaundice in the first week after birth, with unconjugated bilirubin level of 166-260 micromol (201.50 +/- 36.37 micromol). In the postneonatal period the highest bilirubin level was recorded in the fifth week of life and was 87-273 micromol (166.82 +/- 45.06 micromol), which then spontaneously, without interruption of breast-feeding, gradually declined. The decrease of the unconjugated fraction of serum bilirubin between the fourth and fifth week was significant, and after that highly significant. The normalization of serum bilirubin occurred in the seventh and thirteenth week (10.41 +/- 1.68 micromol). Negative consequences of hyperbilirubinemia were not noted in any of the infants. Breast milk jaundice presents a harmless and transitory disorder of bilirubin metabolism. It occurs in healthy breast-fed neonates and young infants. Jaundice is most marked in early neonatal period, and then it gradually declines and disappears between the seventh and thirteenth week.