Newborn jaundice: What parents need to know – Harvard Health Blog

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

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