Jaundice or a yellow discoloration of the skin is a normal phenomenon in more than half of new-born babies. This jaundice may not appear until the fourth or fifth day.
It is due to the normal breakdown of the foetal red blood cells which occurs after birth and the inability of the immature liver to handle this workload properly. In the premature infant the liver may be more immature and unable to cope, so the level of bilirubin or bile in the blood may rise to dangerous heights. This can cause damage to the brain.
When Rh or other blood incompatibilities are present there may be a great increase in the number of red cells destroyed. The number may be greater than the liver’s capacity for handling it and so the jaundice may reach danger levels.
One new method of dealing with the jaundice in each of these situations is to treat the infant by exposing him to light. This treatment hastens the breakdown of the bilirubin and so may prevent it reaching dangerous levels.