Jaundice in newborn babies is common and usually harmless. It causes yellowing of the skin and the whites of the eyes. The medical term for jaundice in babies is neonatal hyperbilirubinemia.Jaundice is caused by the build-up of bilirubin in the blood. Bilirubin is a yellow substance produced when red blood cells, which carry oxygen around the body, are broken down.Jaundice is common in newborn babies because babies have a high number of red blood cells in their blood, which are broken down and r