Kernicterus: Understanding the Dangers of Newborn Jaundice Left Untreated

What is Kernicterus?

Kernicterus is a rare but serious neurological condition that occurs when dangerously high levels of bilirubin in the blood (hyperbilirubinemia) deposit in a baby's brain tissue. These deposits primarily affect areas like the basal ganglia and brainstem, leading to significant neurological damage.

Also known as bilirubin encephalopathy (BE) or bilirubin-induced neurologic dysfunction (BIND), kernicterus causes could be attributed to severe, untreated cases of neonatal jaundice. Without prompt medical intervention, the condition can lead to permanent complications, including movement disorders, hearing loss, vision impairment, and developmental delays.

Kernicterus is preventable through early recognition and treatment of jaundice in newborns, primarily using phototherapy or exchange transfusions to reduce bilirubin levels before they reach dangerous levels

How Common is Kernicterus?

Kernicterus is a rare condition, affecting approximately 1 in every 44,000 newborns in developed countries. This low incidence is due to the routine monitoring and treatment of newborn jaundice, which prevents it from progressing to kernicterus.

What are the Symptoms of Kernicterus?

Kernicterus symptoms in newborns often include extreme jaundice (yellowing of the skin and eyes), lethargy, and poor feeding. As the condition progresses, more severe signs can develop, such as high-pitched crying, unusual posturing (arching of the back), reduced muscle tone, and seizures. Long-term effects may include hearing loss, movement disorders, and intellectual disabilities. Recognising kernicterus symptoms early is crucial for prompt treatment to prevent permanent neurological damage.

Kernicterus Stages

Kernicterus symptoms develop in stages, starting with early signs like jaundice, lethargy, and feeding difficulties.

• Early Stage:
  • Extreme jaundice, with yellowing of the skin, mucous membranes, and whites of the eyes
  • Absent startle reflex (e.g., Moro reflex)
  • Poor feeding or sucking
  • Extreme sleepiness (lethargy) and low muscle tone (hypotonia)
• Middle Stage:
  • High-pitched cry
  • Irritability
  • Arched back and heels (opisthotonus)
  • Muscle spasms and reduced muscle tone
  • Unusual eye movements
• Late Stage:
  • Stupor or coma
  • No appetite
  • Seizures (epilepsy)
  • Stiff, limp, or floppy muscles
  • Strange eye movements
  • Life-threatening complications such as respiratory distress and cardiac issues

What Causes Kernicterus?

Kernicterus causes include severe infant jaundice that is left untreated over time. Jaundice occurs due to high levels of bilirubin, a byproduct of red blood cell breakdown (hemolysis). In newborns, the liver may not be fully developed, making it less effective at removing bilirubin from the blood. If bilirubin levels become too high and are untreated, the bilirubin can cross the blood-brain barrier and deposit in brain tissue, leading to kernicterus. If jaundice is not managed promptly, the excess bilirubin can move out of the blood and collect in the brain, causing permanent damage.

What are the Long-term Effects or Complications of Kernicterus?

The long-term effects of kernicterus complications can be severe and include permanent brain damage, hearing loss, cerebral palsy, seizures and convulsions, and delayed or abnormal motor development.

What are the Risk Factors for Kernicterus?

Certain factors can increase a newborn's risk of developing kernicterus:

• Premature birth: Babies born prematurely are at higher risk due to less mature liver function.
• Rh hemolytic disease: Newborns with Rh hemolytic disease are at high risk for severe jaundice.
• Other hemolytic conditions that cause the breakdown of red blood cells (hemolysis)
• Family history of jaundice or kernicterus
• Inadequate breastfeeding leading to dehydration, which exacerbates jaundice.

How is Kernicterus Diagnosed?

Diagnosing kernicterus involves a combination of clinical evaluation and diagnostic tests to confirm elevated bilirubin levels. Kernicterus causes typically start with untreated severe jaundice, so healthcare providers closely assess symptoms such as extreme jaundice, abnormal posturing, high-pitched crying, and decreased reflexes.

Transcutaneous Bilirubin (TcB) measurement is a non-invasive test often used as a preliminary screening tool. It detects bilirubin levels through the skin. If TcB levels are high, blood tests are conducted to measure serum bilirubin more accurately.

Early diagnosis is critical because untreated kernicterus complications, such as permanent brain damage, hearing loss, and motor disabilities, can become irreversible. Imaging studies like MRI may also be recommended to assess bilirubin deposition in brain tissues.

Kernicterus treatment relies heavily on early detection and intervention, such as phototherapy or exchange transfusions, to lower bilirubin levels and prevent progression to severe complications.

What level of bilirubin causes kernicterus?

Kernicterus develops when a newborn's bilirubin levels become extremely high, a condition called hyperbilirubinemia. Bilirubin is a yellow pigment that naturally forms during the breakdown of red blood cells. Normally, the liver filters bilirubin from the bloodstream. However, a newborn's still-developing liver may struggle to process excess bilirubin, leading to a buildup.

Specifically, kernicterus becomes a risk when bilirubin reaches levels of:

• 25 mg/dL or higher: Considered very high, can lead to kernicterus
• 30 mg/dL or more: Associated with hazardous hyperbilirubinemia and higher kernicterus risk

How is kernicterus treated?

Prompt intervention is essential to manage kernicterus complications, reduce bilirubin levels, and prevent further brain damage. Kernicterus treatment typically includes:

• Phototherapy: Blue-light therapy is a common first-line treatment. It breaks down excess bilirubin in the skin, making it easier for the baby's body to process and eliminate. However, phototherapy alone may not suffice in severe cases.
• Exchange Transfusion: This emergency procedure rapidly reduces bilirubin levels by replacing some of the baby’s blood with donor blood. It is especially crucial in severe cases where bilirubin levels are dangerously high.
• Intravenous Fluids: Maintaining proper hydration supports the baby's liver and kidneys, enhancing bilirubin excretion.
• Feeding Support: Frequent feeding helps the baby excrete bilirubin through stool. If the baby is too weak to feed normally, tube feeding may be required.

Early and aggressive treatment minimises the risk of permanent damage and improves outcomes for affected infants.

How soon after treatment will our child feel better?

The improvement in a child's condition after kernicterus treatment can vary depending on the severity of the hyperbilirubinemia and the stage at which treatment was initiated. If treatment is started early, before severe brain damage occurs, the baby may start to show improvement within a few days, such as reduced jaundice and improved alertness.

However, if the condition has progressed to later stages, recovery may be slower and more complicated. In some cases, babies may start to show signs of improvement within 24 to 48 hours after the initiation of phototherapy or exchange transfusion, but the full extent of recovery and any long-term effects will depend on the severity of the brain damage incurred.

Can kernicterus be prevented?

Yes, kernicterus can be prevented by early detection and treatment of jaundice. Some key preventive measures include:

• Regular Monitoring: Healthcare providers should check babies for jaundice every 8-12 hours in the first 48 hours after birth, especially if there are risk factors for high bilirubin levels.
• Early Treatment: Initiating phototherapy or other treatments as soon as high bilirubin levels are detected can prevent kernicterus.
• Follow-Up Visits: Regular follow-up visits after discharge from the hospital are important to monitor bilirubin levels and ensure that jaundice is not worsening.

What is the outlook for kernicterus?

The outlook for kernicterus depends on the timing and effectiveness of the treatment. Early diagnosis and prompt treatment can lead to a full recovery without long-term complications for many babies. However, if kernicterus is not diagnosed and treated promptly, it can result in severe and permanent brain damage.

Babies who receive treatment while the condition is in the early or middle stage may have a better prognosis, while those with late-stage kernicterus may face life-threatening complications, including hearing loss, cerebral palsy, and neuro-developmental retardation.

Can a baby recover from kernicterus?

Recovery from kernicterus is possible if the condition is diagnosed and treated early. Early intervention, such as phototherapy and exchange transfusions, can help reduce bilirubin levels and prevent further brain damage. However, if significant brain damage has occurred before treatment, the recovery may be incomplete, and the child may experience long-term complications such as cerebral palsy, hearing loss, and developmental delays.

When to see a doctor?

Parents should seek immediate medical attention if they notice any of the following kernicterus symptoms in their newborn:

• Yellowing of the skin and whites of the eyes
• Poor feeding
• Lethargy or extreme sleepiness
• High-pitched cry
• No startle reflex
• Brief pauses in breathing (apnoea)
• Muscles becoming unusually floppy

Early detection and treatment are crucial in preventing kernicterus and minimising its impact.

Conclusion

While kernicterus is rare, parents must be aware of this serious complication of untreated newborn jaundice. By understanding the kernicterus symptoms, causes, and risk factors, you can take timely action to protect your baby's health. If you notice any signs of severe jaundice or kernicterus in your newborn, seek immediate medical attention.

At Metropolis Healthcare, we understand the importance of early diagnosis in preventing complications like kernicterus. Our team of qualified blood collection technicians can make at-home visits for blood samples, which are processed at our advanced diagnostic labs. Test reports are conveniently shared online, empowering you to prioritise your baby's health.