Jaundice in New Born Babies

Jaundice is very common in newborn babies. About 90% will develop jaundice around day four. It happens because the liver is such a complex organ and, despite a baby being full term, it can take a few days for the liver to work efficiently.

One of the many functions of the liver is to remove a waste product made from the breakdown of the red blood cells, called bilirubin. This waste product, unconjugated bilirubin, is processed by the liver by the addition of a "sugar" which changes the bilirubin to conjugated bilirubin.

Newborn babies have a greater number of red blood cells than normal at birth and these are broken down more quickly. Couple this with the liver being slightly inefficient at birth and a build up of unconjugated bilirubin can occur. The unconjugated bilirubin is then picked up by the blood stream and causes the baby to become jaundiced. Jaundice is defined as being yellowing of the skin and the whites of the eyes.

Normally this type of jaundice, often called physiological or baby jaundice, disappears by the time the baby is 10 days old (a bit longer if the baby is premature). The level of bilirubin can be measured in the baby's blood quite simply from a heel prick blood sample. If this "serum bilirubin" level becomes too high there can be a concern that it could cause damage to the baby's brain. This is why a baby is given phototherapy to reduce the bilirubin level. In mild cases of jaundice, the midwife may suggest that the baby is placed in the sunlight. Do be careful that the baby does not overheat or becomes sun burned though.

What else can I do?

If your baby is jaundiced then check the following:

• Stool and urine colour
• The urine of a newly born baby should be colourless
• The stools of a breast fed baby should be green / daffodil yellow colour
• The stools of a bottle fed baby should be green / English mustard colour
  

Build up of conjugated bilirubin

Babies with liver disease can also present with jaundice. Their jaundice, however, is caused by the build of conjugated bilirubin. In these babies the conjugated bilirubin is also picked up by the blood and is passed round the body causing jaundice. It also causes the urine to be yellow as the kidneys try to excrete the conjugated bilirubin, which is water-soluble. Yellow urine in a baby is not normal and the baby should be investigated for liver disease. That's why it is important to check the urine colour.

The stool colour may also give an indication of liver disease. If there is a blockage in the liver or biliary tract it may prevent the bile from draining from the liver. This will mean that the stool will not be so coloured and can appear pale and even clay coloured. Any baby with pale stools or stools which appear very "fatty" in texture should be investigated.

If you are concerned then speak to your midwife, health visitor or doctor.

What needs to be done?

If jaundice continues beyond 14 days of age for a full term baby or 21 days in a premature baby then this should be investigated. It is vital that the stool and urine colour is checked. A split bilirubin blood test should be carried out. This may mean that you will need to take your baby to hospital to have the blood test. This test measures the levels of conjugated and unconjugated bilirubin in the blood. If the conjugated fraction is greater than 20% of the total bilirubin level, this indicates liver disease. The baby should be referred to a specialist liver unit for investigation.

Note: A baby can have normal baby jaundice and jaundice caused by liver disease at the same time.