Excessive jaundice in a newborn kills developing brain cells and may cause mental retardation, physical abnormalities or blindness.

Jaundice is the discoloration of the skin and sclera of the eye caused by abnormally high levels of bilirubin. In adults and other children, jaundice is harmless.  But the tissues protecting the brain (the blood-brain barrier) are immature in newborns.  In newborns, bilirubin can penetrate the brain and literally stains the nerve bodies, causing irreversible damage.  Depending on the level of exposure, the effects range from unnoticeable to severe brain damage (known as kernicterus).

Bilirubin is one of the waste products of red blood cells.  Ordinarily, bilirubin is excreted from the body as the chief component of bile.  Too much bilirubin may means that the function of the newborn's liver is compromised.

Very high levels of bilirubin in the bloodstream can cause permanent damage to certain areas of the brain of newborn infants, known as kernicterus.  Kernicterus is damage to the brain centers of infants caused by jaundice.  The excessive levels of bilirubin can cause a characteristic form of cerebral palsy known as athetoid cerebral palsy.

To prevent this from happening, bilirubin levels are monitored in newborns.  There are two different chemical forms of bilirubin--direct (or conjugated) and indirect (unconjugated) bilirubin. Doctors may order bilirubin tests, along with liver enzyme tests, when jaundice is present.

Excessive levels of bilirubin are treated either by phototherapy ("bilirubin lights") or a blood exchange transfusion.  The bilirubin level can be decreased by exposing newborns to ultraviolet light.

If your newborn has jaundice, it is crucial that his/her doctors carefully monitor the bilirubin levels and begin treatment to reduce the bilirubin levels before irreversible brain damage occurs.