Jaundice is yellow discolouration of the skin and sclera (whites of the eyes) that is seen in newborn babies as a result of the production of a pigment called bilirubin. Bilirubin is increased in newborn babies due to the relatively rapid breakdown of red blood cells together with mild immaturity of the liver.
The majority of newborn babies develop mild jaundice after the first few days of life. Usually this is due to physiological jaundice, which is normal, occurs for the reasons listed above, and resolves spontaneously within the first 7 to 10 days of life. In most cases, no treatment is required however, if the jaundice becomes more severe and/or the baby becomes drowsy and feeds poorly, the bilirubin level can be easily tested by collecting a few drops of blood from a heel prick. Treatment with phototherapy is occasionally required.
Jaundice that starts in the first 24 hours of life may not be physiological. An important cause is haemolysis (bursting of red blood cells), which occurs for several reasons but may be due to a difference between the mother and baby’s blood group. This requires an urgent bilirubin level and may require treatment with supplementary formula feeds and/or phototherapy. Any baby who is unwell with jaundice always requires further investigation.
Prolonged jaundice refers to jaundice that persists longer than two weeks in term babies and three weeks in premature babies. Blood tests may be required to exclude other causes including an underactive thyroid gland and urinary infection but prolonged jaundice is usually due to breast milk jaundice, which is common, of no significance and usually settles by six weeks of age.