What is neonatal jaundice? Neonatal jaundice, also called neonatal hyperbilirubinemia, refers to a condition that causes jaundice due to bilirubin metabolism disorder. This condition is very common in newborns. According to surveys, about 60% of newborns will develop mild jaundice on the 3rd to 5th day after birth. This is a normal physiological phenomenon and usually resolves on its own within a week or two. , but if the symptoms last for a long time or the jaundice appears severe or delayed