Kernicterus and untreated newborn jaundice

How does this happen?

Red blood cells are broken down all the time, and bilirubin is one of the waste products. An adult liver processes it and clears it. A newborn liver takes a few days to get going, so bilirubin builds up. That is why most newborns are a bit yellow in the first week, and why it usually resolves on its own.

The problem starts when the level rises faster or higher than the liver can handle. Bilirubin that is not bound to protein in the blood can cross into the brain, and it is toxic to specific structures: the basal ganglia, and the hearing pathways in the brainstem. ²

That is why kernicterus produces such a specific pattern: a movement disorder plus hearing loss plus difficulty looking upward. ²

Several things push bilirubin up faster: blood group incompatibility between mother and baby, bruising or a cephalohematoma where collected blood breaks down, prematurity, poor feeding and dehydration, infection, and inherited red cell conditions such as G6PD deficiency. ¹

The reason the timing matters so much is that risk is not about a single number. A bilirubin of 15 at 24 hours old is a very different situation from a bilirubin of 15 at 96 hours old. The published thresholds are drawn as curves against the hour of age for exactly that reason. ¹

What causes it?

Two different questions get mixed together here. The first is what leads to this injury in the body. The second is whether anyone could have prevented it. They are not the same question, and the answer to the first does not settle the second.

Happens even with perfect care

• Blood group incompatibility causing rapid red cell breakdown, sometimes despite correct Rh prevention. ³
• G6PD deficiency and other inherited red cell conditions, which can cause a very fast rise. ¹
• Bruising or a cephalohematoma from birth, which adds a load of blood to break down.
• Prematurity, since a less mature liver clears bilirubin more slowly.
• Difficulty establishing feeding, which is common and not anyone's fault.
• Rare inherited conditions in which bilirubin rises despite normal care.

Associated with gaps in care

These are situations where published standards say what the care team should watch for and do. A gap here does not prove anyone caused your child's injury. It points to where the medical records will have an answer.

This is one of the few areas in newborn medicine where the prevention standard is specific, published and time-based.

• Bilirubin never measured before discharge, or measured and not plotted against the hour of age. Guidance sets out universal screening before discharge. ¹
• A level above the treatment threshold not acted on. ¹
• phototherapy started late, or stopped too early, or delivered with inadequate intensity.
• exchange transfusion not done once the level crossed the exchange threshold, or delayed while arrangements were made. ¹
• A baby discharged early without a follow-up plan, when guidance sets out when the baby must be seen again based on age at discharge and the bilirubin level. ¹
• Parents told to sit the baby in a window, or otherwise reassured, instead of a level being measured.
• Warning signs of acute bilirubin encephalopathy not recognized: extreme sleepiness, a high-pitched cry, poor feeding, arching of the neck and back. These signs indicate an emergency. ¹
• Rh immune globulin not given to an Rh-negative mother when indicated. ³

Whether any of this amounts to a departure from the standard of care takes a physician expert reading the whole record. What is different about kernicterus is that the record contains the exact numbers and the exact times, so the question can usually be answered clearly.

What are the signs, by age?

Signs change as a child grows. A newborn cannot show you a walking problem. Some children look fine at first and show differences months later.

At birth and the first hours

Jaundice within the first 24 hours of life is never normal and always needs a bilirubin level. Yellow skin appearing on day one is a red flag. ¹

The first week

Jaundice that is deepening, spreading down the body, or that appears in a baby who is feeding poorly.

Warning signs of acute bilirubin encephalopathy, which are an emergency:

• Extreme sleepiness, or a baby who is hard to wake to feed.
• A high-pitched or shrill cry.
• Poor suck and poor feeding.
• Floppiness, then arching of the neck and back.
• Fever, or a baby who stops moving normally. ¹

Around 3 months

• Failing or missing the newborn hearing screen. ⁴
• Difficulty feeding, with a tongue that pushes food out.
• Fluctuating muscle tone.
• Arching, especially when upset.

Around 6 months

• Movements that are not intended, most visible in the hands and face.
• Poor head control.
• Delay in rolling. ⁵
• Confirmed hearing loss, often of a type called auditory neuropathy, in which the ear works but the signal does not travel properly. ⁶

Around 12 months

• Dyskinetic cerebral palsy becoming clear.
• Not sitting independently. ⁵
• Difficulty looking upward, which is a characteristic finding.

Toddler years

• Twisting postures and unintended movements.
• Speech that is very hard to produce.
• Hearing loss affecting language development.
• Typical intelligence in many children, which is often not recognized.

School age

• Movement and communication needs, usually with AAC.
• Hearing technology and support.
• Learning that is often in the typical range, provided communication and hearing are properly addressed.

How is it diagnosed?

For jaundice

A transcutaneous bilirubin reading is taken with a light meter on the skin as a screen. A high or borderline reading is confirmed with a total serum bilirubin blood test, which is the number the thresholds are based on. ¹

The level is then plotted against the baby's exact age in hours, adjusted for gestational age and risk factors, and compared to the phototherapy and exchange thresholds. ¹

Additional tests when the level is high or rising fast: blood type and Coombs test test on the baby, blood count, and testing for G6PD deficiency where indicated. ¹

For kernicterus

The diagnosis is clinical and supported by imaging and hearing tests.

• MRI typically shows a characteristic abnormality in the globus pallidus on both sides. ²
• Hearing testing, including auditory brainstem response, because bilirubin injures the hearing pathway and standard screening can miss auditory neuropathy. ⁶
• Examination showing a movement disorder, difficulty with upward gaze, and often dental enamel changes later.

What to request if this happened to your baby

Ask for every bilirubin value with the exact time it was drawn and the baby's age in hours at that moment. Also ask for the discharge instructions and the follow-up appointment that was arranged. Those documents together answer most of the questions families have. ¹

What is the treatment?

Treating high bilirubin

phototherapy. Blue light that changes bilirubin into a form the body can excrete. It is safe, it is not painful, and its intensity and the surface area of skin exposed both matter. ¹

Feeding support. Good feeding helps clear bilirubin. Interrupting breastfeeding is not usually necessary and is a common misunderstanding.

Intravenous immunoglobulin, in specific cases of blood group incompatibility. ¹

exchange transfusion. The emergency treatment, used when the level crosses the exchange threshold or when there are signs of acute bilirubin encephalopathy. Time matters. ¹

Treating kernicterus, once it has happened

The brain injury cannot be reversed. Care follows the pattern of dyskinetic cerebral palsy plus hearing loss.

• Medicines for dystonia, seating and positioning, and sometimes a intrathecal baclofen pump.
• Hearing technology, chosen with an audiologist who understands auditory neuropathy. ⁶
• AAC, early, because both speech and hearing are affected.
• Early intervention therapy. ⁷

See dyskinetic cerebral palsy for the movement side in detail.

What is the long-term outlook?

For jaundice treated in time, the outlook is complete recovery with no lasting effects. That is the overwhelming majority of jaundiced newborns. ¹

For kernicterus, the injury is permanent. The typical picture is dyskinetic cerebral palsy, hearing loss often of the auditory neuropathy type, difficulty with upward gaze, and dental enamel changes. ²

Intelligence is frequently in the typical range. This matters enormously, because a child with severe movement and hearing impairment and typical intelligence will be underestimated unless communication and hearing are addressed early and properly. ⁸

What does daily life look like?

Daily life follows dyskinetic cerebral palsy plus hearing loss: seating, communication technology, feeding support, hearing devices, and therapy.

The single most important practical decision is to set up communication and hearing access early and treat the child as a full participant from the start.

For families, this diagnosis often carries a specific kind of grief, because the prevention standard is public and specific. If that is where you are, the parent's own health guide and the corrections and records guides are both on this site. ⁹

What does care cost over a lifetime?

CDC estimated lifetime costs for people born in 2000 at about $921,000 for cerebral palsy and about $417,000 for hearing loss, both in 2003 dollars. ¹⁰

Those are separate population estimates and they cannot simply be added together for one child, because they overlap in the costs they count.

Kernicterus generally sits at the higher end of the cerebral palsy range, because it combines a movement disorder with hearing loss and communication needs. See the cost of care estimator.

What can you do this week?

1. Request every bilirubin value with the exact time and the baby's age in hours. This is the single most important record.
2. Request the discharge summary and the discharge instructions, including what follow-up was arranged and when.
3. Ask what the treatment threshold was for your baby at each measured time.
4. Ask when phototherapy started and stopped, and whether exchange transfusion was considered.
5. Arrange a full audiology assessment, including testing for auditory neuropathy.
6. Ask for a brain MRI if it has not been done.
7. Refer to early intervention today.

What should you ask each specialist?

Take these with you. Write the answers down in the moment, because you will not remember them later.

For the neonatologist or pediatrician

• What were all the bilirubin values, and at what hour of age was each drawn?
• What was the phototherapy threshold and the exchange threshold at each of those times?
• When did phototherapy start, and at what intensity?
• Was exchange transfusion considered, and what was the decision?
• What was the discharge follow-up plan, and was it kept?

For the audiologist

• Is there auditory neuropathy, as opposed to ordinary hearing loss?
• What technology fits this pattern of hearing loss?
• How does this change the communication plan?

For the neurologist

• What did the MRI show in the globus pallidus?
• What movement pattern do you expect, and how will we manage it?
• What is the plan for communication?

You can also build a printable list with the question generator.