Jaundice and Kernicterus:  Treating One to Avoid the Other

Jaundice Kernicterus

Do you know someone whose newborn baby had to stay a day or two in the hospital under a special light?  Or perhaps you’ve had a new arrival whose doctor told you that he needs “a test for jaundice” before he goes home?  Or, just maybe, you’ve not had that experience with your previous baby, but were told by the discharge nurse to call right away for a yellow color.  You may even have learned “jaune” meant “yellow” in your French class and thus have an idea of where the word “jaundice” came from.

Even if you know a little bit about jaundice, and you know that newborns are often treated for it, you may not know exactly why.  What’s the deal?  Why does everyone get concerned about that yellow color?

Bilirubin 101

In order to answer that question, it’s worth looking at what causes jaundice.  It’s due to a chemical in the blood called bilirubin.  Bilirubin is produced when red blood cells—the components of the blood that carry oxygen—break down.  It’s then removed by the liver.

Everyone has some bilirubin circulating in their blood before it’s removed.  Newborns, however, have a higher level for two reasons.  First, they have a higher percentage of circulating red blood cells before they’re born.  At birth, this high concentration is no longer needed, so many of the red cells break down, thus producing bilirubin.

Second, a newborn’s liver doesn’t work as well during those first few days of life.  The liver thus can’t take care of the lot of the bilirubin produced, and the level of the chemical—even in healthy babies—rises much higher than is seen in healthy older people.  And newborns with certain conditions are at greater risk for jaundice.

Kernicterus—The Worst Complication

While a mild degree of jaundice generally won’t harm a baby, the danger comes when bilirubin levels reach a dangerously high level.  A markedly elevated concentration of bilirubin can lead to a rare but devastating complication known as kernicterus.  In this condition, bilirubin settles in parts of the brain.  Since bilirubin seems to prefer to settle in a area of the brain that influences movement, one of the more common complications of kernicterus is athetoid cerebral palsy.  In addition, there may be problems with vision, hearing, dental development, and intellectual function.

Your newborn’s provider might be especially concerned about kernicterus if she has extreme jaundice and begins to show certain behaviors.  She may be sleepy and fail to feed well.  If the bilirubin remains elevated, she may start with a high-pitched cry, a stiffening of the body, and abnormal movements, particularly of the neck and back.  Because true kernicterus is not reversible, physicians take any signs like these very seriously, and will take steps to quickly bring the bilirubin down.

Avoiding Kernicterus

Although kernicterus is rare, because it is such a serious and mostly irreversible complication of newborn jaundice, babies are monitored very carefully for jaundice.  More than 50% of babies will show some yellow color.  The pediatric provider may decide to do a blood test for bilirubin based on several factors:  the baby’s age, how jaundiced he looks, and the presence of risk factors for jaundice.

If the bilirubin is significantly elevated, there is a tried-and-true treatment that usually brings the level down.  The baby is put under a special light which acts to break down the bilirubin into chemicals that the body can easily get rid of.

Rarely, if the bilirubin remains high despite treatment under the light, or—even more unusual—the baby shows signs that the chemical might be settling in the brain, there are more drastic treatments.  The most common of these is called exchange transfusion.  This procedure involves removing some of the newborn’s blood (thus removing the bilirubin) and replacing it with other blood.

Finally, you may be wondering:  is there anything I can do to help reduce my baby’s risk of kernicterus?  Probably the best answer to this question is frequent feeding.  Some bilirubin leaves the body through the bowels, and feeding gets the bowels moving!

Also, it’s important to have early follow up with your pediatric provider, especially if your newborn is discharged on the early side (before 48 hours).  The American Academy of Pediatrics recommends a visit two to three days after discharge, and one reason for this is to monitor infants for jaundice.

If your baby’s provider does decide bilirubin testing and/or treatment is needed, it’s important to follow through with the recommendations.  Providers may choose to have the baby’s blood tested after discharge if the bilirubin is elevated, but not high enough to treat.  And if treatment is needed, be patient—it may take a few days, but it’s generally very effective.  And with rare exceptions, jaundice no longer presents a problem after a few weeks of age!

Stan Sack
Dr. Stan Sack has 29 years’ experience as a primary care pediatrician in Massachusetts and Florida. A medical writer since 2015, he enjoys blogging on topics that are on parents’ minds but are covered less often in books and on websites. He lives in the Florida Keys with his family and enjoys healthy cooking, fitness activities and singing in his spare time.

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