Jaundice is caused by the normal breakdown of red blood cells. This process releases a chemical called bilirubin, which makes the skin yellow. Babies break down red blood cells very quickly, but their livers aren’t developed enough to get rid of bilirubin. This results in a bilirubin overload, which causes physiological jaundice.
Most newborns with jaundice will have ‘breastmilk jaundice’. This is when a chemical in the mother’s breastmilk interferes with getting rid of bilirubin. This type of jaundice usually sorts itself out without treatment, after several weeks.
One rare type of jaundice occurs when the mother’s and the baby’s blood groups are incompatible (usually ABO or Rhesus factor incompatibility). This isn’t usually a problem during a first pregnancy because the mother’s and the baby’s bloodstreams don’t mix. But during the delivery, some of the baby’s blood might mix with the mother’s blood. The mother then develops antibodies that become active during the next pregnancy and cross the placenta to attack a second baby’s red blood cells. Their destruction releases bilirubin into the second baby’s bloodstream, and jaundice occurs. If this has happened, it’s usually seen in the first 24 hours after birth.
Biliary atresia is another rare cause of jaundice in babies. It happens when the tiny tubes that carry bile from the liver to the intestine get scarred. Babies with this condition usually grow normally and look well at first, but they will get very ill with serious liver disease if they aren’t diagnosed and treated early. Their jaundice will usually go on after they are two weeks of age, and they might also have pale-looking poo.
Jaundice in a newborn causes the skin and the whites of the eyes to go a yellow colour. The jaundice typically starts on the face and head. If the level of bilirubin increases, the colour will spread to the body. Babies might also be drowsy and have feeding difficulties.
When to see your doctor
Jaundice is usually harmless, but a nurse or doctor should check and monitor all cases of jaundice in newborn babies. Some babies have severe jaundice, which very occasionally can lead to deafness and even brain damage if not treated promptly.
You should take your baby to the doctor if:
- your baby is unwell, feeding poorly and not gaining enough weight
- your baby’s poo becomes pale or baby’s wee becomes dark
- your baby develops jaundice in the first 48 hours after birth
- the jaundice becomes more noticeable after a week
- the jaundice hasn’t gone away after two weeks.
If your baby has jaundice lasting more than two weeks – especially if his poos are pale or his wees are dark – he’ll need a blood test to check the ‘conjugated bilirubin’ levels in the blood. He might then need more tests on his liver.
Treatment for jaundice depends on how bad it is and what has caused it.
Babies who develop jaundice several days after birth usually just need careful monitoring, sometimes with heel prick blood tests, to check the bilirubin levels in their blood.
If the bilirubin levels are high, babies might have phototherapy treatment for a few days. This treatment uses ultraviolet light to help to break down the bilirubin overload. It involves the baby being placed naked in a cot under a blue phototherapy lamp for 2-3 days. The baby’s eyes will be covered for protection. There are minimal side effects to phototherapy, although the baby might have a mild rash and runny poo for a few days. Some babies have small fluid losses during phototherapy, so they might need extra feeds at this time. Most babies tolerate phototherapy treatment well.
Severe jaundice, in which bilirubin levels are very high, might need treatment with an exchange transfusion. This is when a baby’s own blood is replaced with compatible fresh blood. This isn’t common.
If your baby has breastmilk jaundice, it doesn’t mean that you need to stop breastfeeding. This type of jaundice is usually mild and should get better by itself with time. Talk to your child and family health nurse or doctor if you’re worried about what to do.
Only ‘incompatible blood type’ jaundice is preventable. If this type of jaundice is suspected, the mother will receive an anti-D injection immediately after delivery. This can prevent complications in subsequent pregnancies.