In the breastfed infant, prolongation of unconjugated hyperbilirubinemia into the third and later weeks of life in the healthy newborn is a normal and regularly occurring extension of physiologic jaundice. This is known as breastmilk jaundice. A factor in human milk increases the enterohepatic circulation of bilirubin. Insufficient caloric intake resulting from maternal and/or infant breastfeeding difficulties may also increase serum unconjugated bilirubin concentrations. This is the infantile equivalent of adult starvation jaundice. It is known as breastfeeding jaundice or "breast-nonfeeding jaundice." This increase in severity of physiologic jaundice of the newborn also results from increased enterohepatic circulation of bilirubin, but not because of a factor in human milk. In extreme cases, it may place the infant at risk for development of bilirubin encephalopathy. Optimal breastfeeding practices, which result in minimal initial weight loss and early onset of weight gain, are associated with both reduced breastfeeding jaundice and minimization of the intensity of breastmilk jaundice.