This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Kernicterus refers to brain damage that may occur when neonatal jaundice goes untreated for too long. Physiologic neonatal jaundice (which can affect about 60% of all newborn babies) is a very common condition in which the skin and whites of the eyes are yellowish in color within a few days after birth, due to high levels of a yellow pigment (bilirubin) created when the body gets rid of old red blood cells. However, in some babies, bilirubin levels may rise excessively (hyperbilirubinemia), which can damage the brain cells. Risk factors for severe jaundice and higher bilirubin levels include premature birth (before 37 weeks); darker skin color; East Asian or Mediterranean descent; feeding difficulties; jaundice in a sibling; bruising at birth; and a mother with an O blood type or Rh negative blood factor.
After a few days of jaundice, toxic levels of bilirubin in certain areas of the brain may cause signs and symptoms such as respiratory distress, muscle spasms, and/or low muscle tone (hypotonia). Other symptoms can develop as the baby gets older, such as delayed motor development, seizures, lack of coordination (ataxia), muscle spasms (dystonia), involuntary movements (athetosis), sensory problems, lack of upward gaze, hearing loss, intellectual disability, and difficulty speaking (dysarthria). The term “Bilirubin-induced neurologic dysfunction (BIND)” is used for the signs and symptoms of kernicterus. In most cases, the syndrome develops by 3 to 4 years of age.
Early detection and management of jaundice can prevent kernicterus. Phototherapy is the most commonly used method to prevent bilirubin toxicity. The definitive method of removing bilirubin from the blood is exchange transfusion. While medications are not usually given to babies with physiologic neonatal jaundice, in some cases, phenobarbital (an inducer of liver bilirubin metabolism) has been used to reduce bilirubin levels in the blood during the first week of life.
For more information, visit GARD.