What causes kernicterus?

• A. Exposure to high levels of oxygen
• B. Neurotoxicity from high serum bilirubin levels
• C. Maternal infection during pregnancy
• D. Low birth weight

Answer: (B)

Kernicterus is a severe form of brain damage that occurs as a result of high levels of bilirubin in the blood, a condition known as hyperbilirubinemia. When there is an excessive amount of bilirubin, particularly unconjugated bilirubin, it can cross the blood-brain barrier and deposit in the brain tissues. This neurotoxicity leads to irreversible damage to specific areas of the brain, which may subsequently result in significant neurological impairments such as spasticity, hearing loss, and cognitive deficits.

The key mechanism behind kernicterus is therefore the neurotoxic effects of elevated serum bilirubin levels. It is critical to monitor bilirubin levels in newborns, especially those who are at risk of developing jaundice, to prevent the progression to kernicterus.

Other options may present conditions related to newborn health but do not directly lead to the neurotoxic effects seen in kernicterus. For example, while maternal infection during pregnancy or low birth weight can impact overall health and development, they are not specifically linked to the mechanism of bilirubin toxicity that characterizes kernicterus.