Jaundice in Babies
Jaundice (yellow coloring of the skin and eyes) starting on about the 3rd or 4th day after birth can be seen in about 60% of full term babies (babies who are born after about nine months pregnancy). It is even more common in babies who are born early. Some babies will need treatment for the jaundice, while for most the jaundice will not last long (between 1 and 2 weeks) and not cause problems even without treatment.
What Causes Jaundice?
Jaundice is caused by high levels of a chemical called bilirubin in the baby's body.
Red blood cells are being made, and being broken down continually in all people, including babies before and after birth, because red blood cells, like most other cells in the body, have a limited lifespan, and after several weeks they do not work as well as newly made cells. The protein in the red blood cells that makes them red is called hemoglobin. This protein breaks down into smaller chemicals before it can be eliminated (got rid of) from the body. Bilirubin is one of these chemicals.
Before birth the chemicals made when the baby's hemoglobin breaks down are carried out of the baby through the umbilical cord to the placenta, and into the mother's blood. The mother's body then gets rid of them with her own waste products.
When a baby is born, the baby's liver suddenly has to take over the work of getting rid of hemoglobin and it can take the liver a few days to fully manage this. While this is happening the level of bilirubin in the baby's body rises, causing the yellow color - jaundice.
Which Babies Get Jaundiced?
All babies have a raised bilirubin level for several days, but in healthy full term babies this may not be noticeable, or if it is, the level is usually still low and not a problem.
Some babies who have a lot of bruising when they are being born also have a lot of damaged red blood cells (in the bruise) which need to be broken down, and these babies can develop a high bilirubin level.
Some breast-fed babies (about 5%) will also have higher levels of bilirubin, in part due to some of the chemicals that are naturally in the breast milk (including an enzyme called ί-glucuronyl transferase). In the early days after birth, before the breast milk 'comes in' the baby may be getting less fluid and less calories than in a bottle fed baby (this is not harmful) slowing down the elimination of bilirubin. 'Breastfeeding jaundice' may last for several weeks.
In some babies, especially premature babies, or ones who are sick for some other reason (e.g. they have an infection), the bilirubin level goes higher, and a very high bilirubin level can cause some severe health problems.
Some babies who have a blood group different to their mother's blood group may also have jaundice
