Kernicterus is brain damage in infants caused by high levels of bilirubin in the blood. This condition occurs when jaundice is not treated immediately so that bilirubin levels continue to increase and cause damage to the brain.

Kernicterus generally affects babies because jaundice often occurs in babies. This is because the baby's liver is still slow in processing bilirubin. Meanwhile, kernicterus in adults usually only occurs due to genetic disorders that affect the processing of bilirubin .

Although it is a rare condition, kernicterus is very dangerous and can result in brain injury or cerebral palsy ( cerebral palsy ). In addition, kernicterus can also cause problems with teeth, disturbances in vision and hearing, and mental retardation.

Causes of Kernicterus

Kernicterus is caused by high levels of bilirubin in the blood (hyperbilirubinemia) which is characterized by yellowing of the body. This condition, known as jaundice , is estimated to be experienced by 60% of babies.

Bilirubin is a waste product that is produced naturally when the body recycles red blood cells. Bilirubin levels that exceed normal values ​​are common in newborns. This is because the baby's body still needs to adapt to get rid of bilirubin.

Increased levels of bilirubin in infants can occur on the third day after birth and can continue to increase until the 5th day. After that, the bilirubin level will gradually decrease until the jaundice on the baby's body disappears by itself within 2-3 weeks.

However, some jaundice caused by certain conditions can develop into kernicterus, because in this condition the level of bilirubin continues to increase. This condition is very dangerous because the bilirubin can spread to the brain and cause permanent brain damage.

Some of the causes of jaundice that can develop into kernicterus are:

  • Red blood cell disorders, eg thalassemia
  • Rhesus incompatibility (the blood rhesus of the baby and the mother is not the same)
  • Bleeding under the scalp ( cephalohematoma ) that forms when a baby is born
  • High red blood cell levels are common in twins or babies with low birth weight
  • Lack of enzymes that cause red blood cells to break down more easily
  • Medical conditions that affect the liver or bile ducts, such as hepatitis and cystic fibrosis
  • Lack of oxygen (hypoxia)
  • Infections that occur in the womb or at birth, such as syphilis or rubella
  • Genetic disorders, such as Crigler-Najjar syndrome , Dubin-Johnson syndrome , or Gilbert syndrome

Kernicterus Risk Factors

There are several factors that can increase the risk of kernicterus in infants, namely:

  • Premature birth
    The liver in babies who are less than 37 weeks in the womb does not develop properly and removes bilirubin more slowly.
  • Blood type O or rhesus negative
    Babies born to mothers with blood type O or negative rhesus are more at risk of having high bilirubin levels.
  • History of jaundice in the family
    The risk of developing kernicterus in infants will be higher if the family has a hereditary history of jaundice. An example of inherited jaundice is glucose-6-phosphate dehydrogenase deficiency .
  • Lack of food intake
    Bilirubin excreted with feces. Therefore, a lack of food intake can make fecal elimination slow so that the level of bilirubin in the body increases.

Symptoms of Kernicterus

The main symptom of kernicterus is jaundice, which is yellowing of the skin and sclera (the whites of the eyes). Jaundice generally appears 3 days after the baby is born and will disappear after 2-3 weeks.

However, if it lasts longer and is not treated, jaundice can develop into kernicterus which is characterized by the following complaints:

  • Fever
  • Easy to fall asleep
  • Weak
  • Vomit
  • Abnormal eye movements
  • Stiff all over
  • Muscles tighten or even weaken
  • Unwilling to breastfeed
  • A squeaky voice when crying
  • Unusual body movements
  • Hearing disorders
  • seizures

When to see a doctor

As mentioned above, jaundice is common in babies and will go away on its own. However, an examination to the doctor must be done immediately if:

  • Jaundice has not improved after more than 5 days
  • Jaundice accompanied by fever, lethargy, or any of the other symptoms above
  • Baby's skin looks very yellow (bright yellow)

If the baby is not delivered at the doctor or hospital, take the baby to the doctor for a thorough examination. The doctor will check for signs of jaundice within 3 days after birth.

Diagnosis of Kernicterus

The diagnosis of kernicterus is based on complaints that occur in infants. In addition to observing the baby's skin and sclera, the doctor will check blood bilirubin levels. In infants with kernicterus, bilirubin levels can be more than 25–30 mg/dL.

In addition, the doctor will also carry out further examinations to determine the conditions that cause jaundice in babies . Examinations that can be done are blood tests to detect blood disorders or infections and check liver function.

Kernicterus Treatment

Treatment for kernicterus aims to reduce the level of bilirubin in the blood and prevent damage to the baby's brain.

In baby mothers with kernicterus, one simple way that can be done is to provide sufficient intake of breast milk or formula milk. Adequate breastfeeding or formula milk can maintain body fluid levels and help remove bilirubin through urine and feces.

Meanwhile, medical actions that can be carried out by doctors are:


Phototherapy or blue light therapy aims to lower bilirubin levels in the blood using special light. Phototherapy can be done with two methods, namely the conventional method and the fiberoptic method.

Conventional phototherapy is done by laying the baby under a halogen or fluorescent lamp. After all the baby's clothes are removed and the baby's eyes are closed, the baby's skin will be exposed to blue light. Meanwhile, in fiberoptic phototherapy, the baby will lie on a mat equipped with a fiberoptic cable to be irradiated on the back.

Phototherapy is generally carried out continuously with breaks of 30 minutes every 3 or 4 hours. The pause is intended so that the mother can feed and change the baby's diaper.

If the baby has not improved after undergoing this therapy, the doctor will recommend a combination of phototherapy using more than one beam and using a fiberoptic mat. This combination therapy is carried out continuously. Therefore, food and fluid intake will be given through an IV.

During phototherapy, the bilirubin level will be checked every 4–6 hours. If the level decreases, the examination will be reduced to every 12 hours. Generally, it takes 2–3 days for the bilirubin level to drop and reach a safe level.

Exchange transfusion

If the bilirubin level in the baby is still high even though he has undergone phototherapy, the doctor will suggest an exchange transfusion. This procedure is done by replacing the baby's blood with donor blood.

Exchange transfusions can take up to several hours. After the transfusion, the baby's bilirubin level will be checked every 2 hours. If the bilirubin level is still high, the exchange transfusion will be repeated.

It should be noted that brain damage from kernicterus cannot be repaired. However, treatment can prevent further brain damage. This is why newborn babies must be monitored closely. Apart from being a prevention, rapidly increasing bilirubin levels can be treated earlier.

Kernicterus complications

A number of complications that can arise in babies with kernicterus are:

  • Athetoid cerebral palsy , which is movement disorder due to brain damage
  • Disorders of eye movement, for example the eye cannot glance up
  • Stains on baby teeth
  • Hearing loss to deafness
  • Mental retardation
  • Hard to talk
  • muscle weakness
  • Impaired control of movement

Prevention of Kernicterus

In the hospital, newborns will generally be observed every 8–12 hours for the first 2 days after birth. Re-observations will also be carried out before the baby is 5 days old.

If on observation the baby looks yellow, the doctor will do a blood bilirubin check. Normally, the level of bilirubin in newborns is below 5 mg/dL. In addition, the doctor will also evaluate risk factors for jaundice and kernicterus in infants to decide whether the baby needs special treatment.

For mothers who have just given birth, it is important to take their control babies to the doctor within 2-3 days after leaving the hospital. This is so that medical examination and treatment can be carried out immediately if jaundice in infants does not improve.

Back to blog