For new parents, it is natural to want reassurance that your baby is healthy, and you may be concerned if your baby develops jaundice. Newborn jaundice is a common condition and is usually treated effectively or doesn’t require treatment at all, but on rare occasions it can develop into kernicterus, which can cause lifelong complications that are often preventable.

The medical negligence solicitors at JMW specialising in kernicterus claims explain the signs of kernicterus, the risk factors that may increase the chance of a baby developing the condition, and how it is diagnosed and treated.

What Is Kernicterus?

Kernicterus is a rare but often preventable type of brain damage that develops in newborn babies when severe jaundice is not recognised or treated in time. Newborn jaundice or physiological jaundice itself is relatively common and causes the skin and the whites of the eyes to appear yellow because of high levels of bilirubin in the blood. Bilirubin is a substance produced when red blood cells break down, and in most cases the liver processes and removes it from the body. However, kernicterus occurs in some babies when too much bilirubin continues to rise to a dangerous point and the baby's liver is unable to remove it.

If bilirubin becomes too concentrated in the baby's body, it can cross the blood-brain barrier and affect areas of the brain that control movement, hearing, vision, and learning. In its early stages of newborn jaundice, this is referred to as acute bilirubin encephalopathy. Without urgent treatment, the condition can progress to kernicterus, causing irreversible damage to the central nervous system.

Although kernicterus is rare, it is considered preventable because newborn jaundice can usually be identified through monitoring and timely treatment.

What Are the Symptoms of Kernicterus?

Kernicterus often develops from severe jaundice that has not been treated in time. Recognising the early warning signs can make a difference in preventing long-term harm. Some of the symptoms may appear mild at first but can progress quickly, so it is important that they are taken seriously. Early signs to look out for include:

• Poor feeding: the baby may refuse feeds or struggle to suck effectively.
• Irritability: they may seem unsettled or more difficult to comfort than usual.
• A high-pitched cry: the cry can sound different to a baby’s normal cry and may be piercing or continuous.
• Loss of the startle reflex: babies normally have a reflex movement when startled, and its absence can be a warning sign.
• Lethargy (sleepiness): the baby may seem excessively tired, drowsy, or hard to wake.
• Apnoea (pauses in breathing): short interruptions in breathing may occur, which can be alarming to see.
• Unusually floppy muscles: the baby may feel limp, sometimes described as being like a rag doll when held.

If a baby shows any of the symptoms of kernicterus, urgent medical assessment is needed. Prompt recognition and treatment of high bilirubin levels can usually prevent kernicterus from developing.

What Are the Risk Factors for Developing Jaundice and Kernicterus?

While jaundice is relatively common in newborns, certain factors increase the likelihood of it becoming more severe and, in rare cases, progressing to kernicterus if not identified and treated in time. 

Yellowing of the skin is often the first sign of jaundice, but yellow pigment can be harder to detect in babies with darker skin tones, which may delay recognition. However, yellowing of the whites of the eyes can be a sign of jaundice that can be easily identified, and should always be checked.

Risk factors also include:

• Premature birth: babies born before 37 weeks of pregnancy are more at risk because their livers are less mature and may not process bilirubin as effectively.
• Poor feeding: if a baby is not feeding well, they may not poo as often. This reduces the body’s ability to clear bilirubin, allowing levels to build up more quickly.
• Family history of severe jaundice: babies with siblings who required treatment for jaundice may be more likely to develop it themselves.
• Blood group incompatibility: when the mother and baby have different blood groups, such as Rh or ABO incompatibility, the baby’s red blood cells may break down more quickly, raising bilirubin levels.
• Birth injuries: a difficult delivery that causes bruising can increase the breakdown of red blood cells, which produces more bilirubin.
• Certain genetic conditions: inherited problems with how the body processes red blood cells or bilirubin, such as glucose-6-phosphate dehydrogenase (G6PD) deficiency, can also raise the risk.

How Is Kernicterus Diagnosed and Treated?

When kernicterus signs are found in a baby, doctors will usually carry out blood tests to measure unconjugated bilirubin levels. These tests analyse the baby’s red blood cells and calculate the total serum bilirubin, which indicates how much bilirubin is present in the body. The results guide doctors on whether treatment is needed urgently to prevent the condition from progressing to acute bilirubin encephalopathy or kernicterus.

If treatment is required, the first step is often light therapy or phototherapy in a neonatal intensive care unit. This involves placing the baby under a special blue light, which helps to break down the excess bilirubin in the baby's skin so that the body can process and remove it more easily. Phototherapy is safe, painless, and usually very effective when started quickly.

In situations where bilirubin levels are extremely high, or if they do not improve with phototherapy, doctors may recommend an exchange transfusion. This is a more intrusive procedure where small amounts of the baby’s blood are gradually replaced with donor blood. By rapidly reducing bilirubin levels, this treatment can protect the brain and lower the risk of permanent damage.

Close monitoring of bilirubin levels during and after treatment is essential, and with timely care, the progression from severe jaundice to kernicterus can usually be avoided.

Why is Prompt Treatment of Kernicterus Important?

Kernicterus is preventable if severe jaundice is recognised and treated early, but when bilirubin reaches very high levels, significant brain damage occurs, causing chronic bilirubin encephalopathy. This is why swift diagnosis and treatment are so important for newborn babies who show signs of jaundice or related complications.

If treatment is delayed, kernicterus can lead to a range of serious and lifelong conditions, including:

• Cerebral palsy: affecting movement, posture and coordination, often making everyday activities more difficult.
• Hearing loss: which may vary from mild difficulties to complete, irreversible loss of hearing.
• Learning disabilities: that can affect a child’s ability to reach developmental milestones and progress at school.
• Involuntary movements: such as twitching or jerking of different parts of the body, which can interfere with daily life.
• Eye movement problems: where children may have difficulty keeping their eyes focused straight ahead, with a tendency to gaze upwards or from side to side.
• Dental issues: including poor or abnormal development of the teeth.

By identifying severe jaundice early and beginning treatment without delay, doctors can usually prevent bilirubin from reaching dangerous levels and stop kernicterus from developing. This helps protect a newborn infant from long-term complications and supports their healthy growth and development. However, if kernicterus is missed, or if a baby is misdiagnosed and treatment is not provided when needed, the outcome can be very different. A delayed kernicterus diagnosis or mismanagement in these circumstances may amount to medical negligence.