Jaundice is a common condition in newborn babies that causes yellowing of the skin and the whites of their eyes.
Jaundice in newborn babies up to a week old is called ‘physiological jaundice’. Jaundice that lasts for more than two weeks is called ‘prolonged jaundice’. Both types are generally considered to be harmless.
Bilirubin
Jaundice is caused by the build up of bilirubin in the blood. Bilirubin is a yellow-coloured substance that is produced when red blood cells are broken down.
The liver should filter the bilirubin from the blood, and change it into a form that allows it to be passed through the gut. It is then excreted (passed out) from the body in faeces (stools). In newborn babies, the bilirubin builds up too fast for the liver to filter it all out, causing jaundice. This can occur because:
- newborn babies have more red blood cells than adults, and the red blood cells have a shorter lifespan, and
- the breakdown and removal of bilirubin is slower in newborn babies than in adults.
How common is jaundice in newborn babies?
Jaundice is very common, occurring in around 60% of newborn babies during their first week of life. This figure rises to 80% in pre-term babies (babies born early). Jaundice is more common in babies who are breastfed, and around 10% of breastfed babies will still have jaundice when they are one month old.
Outlook
Jaundice is usually harmless and disappears in around two weeks without treatment. However, medical attention is necessary if:
- the baby is still jaundiced after two weeks,
- the jaundice does not start until the baby is seven days old, or
- the baby’s faeces (stools) are chalky white.
If the jaundice does not improve, phototherapy (treatment using light) can be used to speed up the removal of bilirubin from the blood. An exchange transfusion (blood transfusion) can also be used. This replaces some of the baby’s blood with donor blood that does not contain bilirubin.
A complication, called kernicterus, can develop if the bilirubin in the blood enters the brain, leading to brain damage or death. However, this is very rare, occurring in less than one baby for every 100,000 live births
