Most newborn babies turn at least a little bit yellow. Known as jaundice, this condition is a very common and usually normal part of the newborn period. But in some very rare cases it can lead to (or be a sign of) a more serious problem. That’s why parents need to know about it.
What causes jaundice?
The yellow color of newborn jaundice is caused by high levels of a substance called bilirubin in the blood. Bilirubin mostly comes from the breakdown of red blood cells. It gets processed in the liver to make it easier for the body to get rid of through the urine and stool.
Newborn livers need some time to get up and running when it comes to getting rid of bilirubin. Newborns also have more red cells than older children and adults, and those brand-new red cells don’t last as long as the ones that get made as babies grow older. The combination of these two factors is what makes jaundice so common.
Jaundice usually peaks in the first two to five days of life, and lasts about one to two weeks. In babies who are breastfed, it can last longer; we don’t know exactly why this happens, but it isn’t anything to worry about.
Jaundice may actually be protective of babies, because bilirubin is an antioxidant that may help fight infection in newborn infants. This is another reason why parents shouldn’t be too worried by a bit of yellowness: not only is it temporary, but it may also be helping their baby as he or she leaves the security of the womb.
Rarely, jaundice may signal a problem
Sometimes, though, jaundice can be a sign of another problem, and when bilirubin levels get very high it can affect the brain, sometimes in a permanent way. This is very, very rare, affecting far less than 1% of infants.
There are many conditions that can make it more likely that bilirubin levels will be high, including:
- Dehydration or inadequate calories. This most commonly happens when babies are exclusively breastfed and a problem with breastfeeding goes unrecognized.
- The systems that work to get rid of bilirubin may just not be ready yet.
- Infection, or a blockage of the intestine. Jaundice would not usually be the only symptom of this.
- ABO or Rh incompatibility. When mother and baby have differences in their blood types, it can lead to more breakdown of red cells than usual. This is something that obstetricians are very aware of, and testing is done whenever there is a concern.
- Bruising or a cephalohematoma (a lump or a bruise on the head). Both can happen during a difficult birth. These lead to more red cells breaking down.
- Liver diseases. There are a number of different liver problems that can make it harder for the baby’s body to get rid of bilirubin.
- Diseases that affect an important enzyme. Some diseases, such as Gilbert syndrome or Crigler-Najjar syndrome, lead to a problem with an enzyme that is important for getting rid of bilirubin.
- Genetic factors. Not all of these factors are well understood. If one baby in a family has jaundice, future babies may have a higher risk too. Babies of East Asian descent, for example, are more likely to have higher bilirubin levels.
Babies are monitored closely for jaundice in the newborn period. Very often, pediatricians use a blood test or a device that measures the bilirubin level through the skin. Based on the result and any risk factors, they decide whether more monitoring or tests are needed, and whether the baby needs therapy.
How is newborn jaundice treated?
The most common therapy, used for the vast majority of babies whose bilirubin levels get worrisome, is phototherapy. The baby is put under a special light (or wrapped in a special blanket with the light inside it) that helps the body get rid of bilirubin. This is safe and effective. When levels are extremely high and there is concern for the possibility of brain damage, therapies such as exchange transfusion, where blood is taken out and new blood put back in, are necessary. However, this is extremely rare.
Feeding is an important part of therapy as well, as it helps the body get rid of bilirubin through the blood and urine. Feeding a newborn frequently can also help prevent problems with jaundice. Babies should wet at least six diapers over a 24-hour period, and should have stools regularly. The stool should change from the normal newborn black, tarry stools to stools that are lighter in color, and looser and “seedy.”
What do parents need to know about newborn jaundice?
It’s important for parents to keep an eye on their baby’s jaundice when they go home from the hospital. Jaundice can be harder to see in dark-skinned babies. A good way to look for it is to press down for a moment on the baby’s skin in a spot where the bone is close (the forehead, nose, chest, or shin are good places to do this). This pushes out the blood briefly and should make the skin paler for a few seconds. If it looks yellow instead of pale, there may be jaundice.
Jaundice tends to spread from the face downward as bilirubin levels go up. For that reason, doctors worry far less about a baby who is yellow just in the face and upper chest than one who is yellow below the knees.
Call the doctor if your baby
- is looking more yellow, especially if it is spreading down below the knees
- is feeding poorly, and/or isn’t wetting at least six diapers in 24 hours and having regular stools
- is very sleepy, especially if they don’t wake to feed
- is very fussy and hard to console
- arches their head or back, or is otherwise acting strangely
- has a fever or is vomiting frequently.
Remember: jaundice is common, and serious problems are rare! But call your doctor if you are worried; it’s always better to be safe than sorry.
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