When to get medical advice
Your baby will be examined for signs of jaundice within 72 hours of being born as part of the newborn physical examination.
While jaundice is not usually a cause for concern, it's important to determine whether your baby needs treatment.
Why does my baby have jaundice?
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 replaced frequently.
Also, a newborn baby's liver is not fully developed, so it's less effective at removing the bilirubin from the blood.
By the time a baby is about 2 weeks old, their liver is more effective at processing bilirubin, so jaundice often corrects itself by this age without causing any harm
In a small number of cases, jaundice can be the sign of an underlying health condition. This is often the case if jaundice develops shortly after birth (within the first 24 hours).
How common is newborn jaundice?
Jaundice is one of the most common conditions that can affect newborn babies.
It's estimated 6 out of every 10 babies develop jaundice, including 8 out of 10 babies born prematurely before the 37th week of pregnancy.
But only around 1 in 20 babies has a blood bilirubin level high enough to need treatment.
For reasons that are unclear, breastfeeding increases a baby's risk of developing jaundice, which can often persist for a month or longer.
But in most cases, the benefits of breastfeeding far outweigh any risks associated with jaundice.
Treating newborn jaundice
Treatment for newborn jaundice is not usually needed because the symptoms normally pass within 10 to 14 days, although they can occasionally last longer.
Treatment is usually only recommended if tests show very high levels of bilirubin in a baby's blood.
This is because there's a small risk the bilirubin could pass into the brain and cause brain damage.
If your baby's jaundice doesn't improve over time or tests show high levels of bilirubin in their blood, they may be admitted to hospital and treated with phototherapy or an exchange transfusion.
These treatments are recommended to reduce the risk of a rare but serious complication of newborn jaundice called kernicterus, which can cause brain damage.
Phototherapy
Phototherapy is treatment with a special type of light (not sunlight).
It's sometimes used to treat newborn jaundice by lowering the bilirubin levels in your baby's blood through a process called photo-oxidation.
Photo-oxidation adds oxygen to the bilirubin so it dissolves easily in water. This makes it easier for your baby's liver to break down and remove the bilirubin from their blood.
During phototherapy, you baby's temperature will be monitored to ensure they're not getting too hot, and they'll be checked for signs of dehydration.
Intravenous fluids may be needed if your baby is becoming dehydrated and they aren't able to drink a sufficient amount.
Phototherapy will be stopped when the bilirubin level falls to a safe level, which usually takes a day or two.
Phototherapy is generally very effective for newborn jaundice and has few side effects, although your baby may develop a temporary rash and diarrhoea.
