Jaundice in Babies: What is it?

Jaundice is caused by bilirubin. Bilirubin is a yellow pigment that is released as a by-product when haemoglobin, contained within red blood cells, is broken down.

Newborn babies have much higher numbers of red cells and their livers are less mature, and so they are less efficient at converting bilirubin into a form that can be removed from the body in their poo and wee. This is why babies commonly develop jaundice within a few days of birth.

The yellow bilirubin builds up causing their skin to have a yellow appearance. The yellow colouring can also be seen in the whites of an infant's eyes.

Comparing your skin colour with your babies is often helpful. Their skin can appear tanned or olive in colour. This is most visible on their hands, feet, and face.

Jaundice is not usually dangerous for babies. However, there are some cases where jaundiced infants might require treatment if their jaundice level rises above a certain level. The treatment threshold varies according to the age of the baby and whether they have been born prematurely.

The following babies are more likely to develop jaundice that needs treatment:

• Babies who were born prematurely (at less than 38 weeks of pregnancy)
• Babies who have a sibling who had jaundice that needed treatment as a baby
• Babies who have signs of jaundice in the first 24 hours after birth.

Whether your baby looks jaundiced or not, the doctor or midwife should check whether your baby is at risk of developing high levels of jaundice soon after birth.

Jaundice under 24 hours of age always needs a medical assessment including a blood test, to check for more serious illnesses.

Untreated severe jaundice can lead to serious risks of developing permanent brain damage. This is known as kernicterus. Fortunately kernicterus is very rare in the UK, affecting less than 1 in every 100,000 babies born.

The symptoms of jaundice usually pass within 10 to 14 days and will clear without medical treatment. Regular feeding is encouraged to help.

Treatment for jaundice will only be recommended if blood 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.

There are two main treatments that can be carried out:

• Phototherapy – a special type of light is shone onto the baby’s skin. This helps the bilirubin change into a form that can be more easily removed from the body in wee and poo. This is very commonly used on postnatal, neonatal and paediatric wards.
• An exchange transfusion – blood is taken from the baby using a thin tube (catheter) and replaced with blood from a matching donor. This is procedure is only needed in the most severe cases.

Most babies respond very well to phototherapy treatments and are able to leave the hospital after a few days.

The following symptoms are signs that the jaundice is becoming more severe and you should always seek medical advice or attend an emergency department.

• A high temperature
• Vomiting
• Refusal to feed and dry nappies
• Lethargy/sleepier than expected

Contact your paediatrician, GP or health visitor if your baby has jaundice that doesn’t go away after more than two weeks, especially if poos look pale and urine appears dark.