Overview

Jaundice in newborn babies is common and usually harmless. It causes yellowing of the skin and the whites of the eyes. The medical term for jaundice in babies is neonatal jaundice.

Yellowing of the skin can be more difficult to see in brown or black skin. It might be easier to see on the palms of the hands or the soles of the feet.

Other symptoms of newborn jaundice can include:

• dark, yellow urine (a newborn baby's urine should be colourless)
• pale-coloured poo (it should be yellow or orange)

The symptoms of newborn jaundice usually develop 2 days after the birth and tend to get better without treatment by the time the baby is about 2 weeks old.

Your baby will be examined for signs of jaundice within 72 hours of being born as part of the newborn physical examination.

If your baby develops signs of jaundice after this time, speak to your midwife, health visitor or a GP as soon as possible for advice.

While jaundice is not usually a cause for concern, it's important to determine whether your baby needs treatment.

If you're monitoring your baby's jaundice at home, it's also important to contact your midwife straight away if your baby's symptoms quickly get worse or they become very reluctant to feed.

Why does my baby have jaundice?

Jaundice is caused by the build-up of bilirubin in the blood. Bilirubin is a yellow substance produced when red blood cells, which carry oxygen around the body, are broken down.

Jaundice is common in newborn babies because babies have a high number of red blood cells in their blood, which are broken down and replaced frequently.

Also, a newborn baby's liver is not fully developed, so it's less effective at removing the bilirubin from the blood.

By the time a baby is about 2 weeks old, their liver is more effective at processing bilirubin, so jaundice often corrects itself by this age without causing any harm.

In a small number of cases, jaundice can be the sign of an underlying health condition. This is often the case if jaundice develops shortly after birth (within the first 24 hours).

How common is newborn jaundice?

Jaundice is one of the most common conditions that can affect newborn babies.

It's estimated 6 out of every 10 babies develop jaundice, including 8 out of 10 babies born prematurely before the 37th week of pregnancy.

But only around 1 in 20 babies has a blood bilirubin level high enough to need treatment.

For reasons that are unclear, breastfeeding increases a baby's risk of developing jaundice, which can often persist for a month or longer. 

But in most cases, the benefits of breastfeeding far outweigh any risks associated with jaundice.

Treating newborn jaundice

Treatment for newborn jaundice is not usually needed because the symptoms normally pass within 10 to 14 days, although they can occasionally last longer.

Treatment is usually only recommended if tests show very high levels of bilirubin in a baby's blood.

This is because there's a small risk the bilirubin could pass into the brain and cause brain damage.

There are 2 main treatments that can be carried out in hospital to quickly reduce your baby's bilirubin levels.

These are:

• phototherapy – a special type of light shines on the skin, which alters the bilirubin into a form that can be more easily broken down by the liver
• an exchange transfusion – where your baby's blood is removed using a thin tube (catheter) placed in their blood vessels and replaced with blood from a matching donor; most babies respond well to treatment and can leave hospital after a few days

Complications

If a baby with very high levels of bilirubin is not treated, there's a risk they could develop permanent brain damage. This is known as kernicterus.

Kernicterus is very rare in the UK.

You can also read the National Institute for Health and Care Excellence (NICE) guidance about jaundice in newborn babies under 28 days.

Symptoms

If your baby has jaundice, their skin will look slightly yellow.

Changes in skin colour can be more difficult to see if your baby has brown or black skin.

Yellowing may be more obvious elsewhere, such as:

• in the whites of their eyes
• inside their mouth
• on the soles of their feet
• on the palms of their hands

The yellowing of the skin is usually more noticeable on the head and face.

The yellowing may also increase if you press an area of skin down with your finger.

A newborn baby with jaundice may also:

• be sleepy
• not want to feed or not feed as well as usual
• have dark yellow pee (it should be colourless)
• have pale poo (it should be yellow or orange)

Jaundice usually appears about 2 days after birth and disappears by the time the baby is 2 weeks old.

In premature babies, who are more prone to jaundice, it can take 5 to 7 days to appear and usually lasts about 3 weeks.

It also tends to last longer in babies who only have breast milk, affecting some babies for a few months.

When to get medical advice

Your baby will usually be examined for signs of jaundice within 72 hours of being born as part of the newborn physical examination.

If your baby develops any signs of jaundice after this time, speak to your midwife, health visitor or a GP as soon as possible for advice.

In most cases, jaundice is harmless and is not a sign of an underlying condition.

It usually clears up on its own by the time a baby is 2 weeks old.

While jaundice is not usually a cause for concern, it's important to determine whether your baby needs treatment.

Who can get it

Jaundice is caused by too much bilirubin in the blood. This is known as hyperbilirubinaemia.

Bilirubin is a yellow substance produced when red blood cells, which carry oxygen around the body, are broken down.

The bilirubin travels in the bloodstream to the liver. The liver changes the form of the bilirubin so it can be passed out of the body in poo.

But if there's too much bilirubin in the blood or the liver can't get rid of it, the excess bilirubin causes jaundice.

Jaundice in babies

Jaundice is common in newborn babies because babies have a high number of red blood cells in their blood, which are broken down and replaced frequently.

A newborn baby's liver isn't fully developed, so it's less effective at processing the bilirubin and removing it from the blood.

This means the level of bilirubin in babies can be about twice as high as in adults.

By the time a baby is around 2 weeks old, they're producing less bilirubin and their liver is more effective at removing it from the body.

This means the jaundice often corrects itself by this point without causing any harm.

Breastfeeding

Breastfeeding your baby can increase their chances of developing jaundice.

But there's no need to stop breastfeeding your baby if they have jaundice as the symptoms normally pass in a few weeks.

The benefits of breastfeeding outweigh any potential risks associated with the condition.

If your baby needs to be treated for jaundice, he or she may need extra fluids and more frequent feeds during treatment.

It's unclear why breastfed babies are more likely to develop jaundice, but a number of theories have been suggested.

For example, it may be that breast milk contains certain substances that reduce the ability of the liver to process bilirubin.

Newborn jaundice thought to be linked to breastfeeding is sometimes called breast milk jaundice.

Underlying health conditions

Sometimes jaundice may be caused by another health problem. This is known as pathological jaundice.

Some causes of pathological jaundice include:

• an underactive thyroid gland (hypothyroidism) – where the thyroid gland doesn't produce enough hormones
• blood group incompatibility – when the mother and baby have different blood types, which are mixed during the pregnancy or the birth
• rhesus factor disease – a condition that can occur if the mother has rhesus-negative blood and the baby has rhesus-positive blood
• a urinary tract infection (UTI)
• Crigler-Najjar syndrome – an inherited condition that affects the enzyme responsible for processing bilirubin
• a blockage or problem in the bile ducts and gallbladder – the gallbladder stores bile, which is transported by the bile ducts to the gut

An inherited enzyme deficiency known as glucose 6 phosphate dehydrogenase (G6PD) could also lead to jaundice or kernicterus.

It's important to let your midwife, GP or paediatrician know if you have a family history of G6PD. Your baby's jaundice symptoms will need to be closely monitored.

Diagnosis

Your baby will be checked for jaundice within 72 hours of being born during the newborn physical examination.

But you should check for symptoms of jaundice after you return home because it can sometimes take up to a week to appear.

When you're at home with your baby, look out for yellowing of their skin or the whites of their eyes. 

Gently pressing your fingers on the tip of their nose or on their forehead can make it easier for you to spot any yellowing.

You should also check your baby's urine and poo. Your baby may have jaundice if their urine is yellow (a newborn baby's urine should be colourless) or their poo is pale (it should be yellow or orange).

Speak to your midwife, health visitor or GP as soon as possible if you think your baby may have jaundice.

Tests will need to be carried out to see whether treatment is needed.

Visual examination

Your baby will have a visual examination to look for signs of jaundice.

They need to be undressed during this so their skin can be looked at under good, preferably natural, light.

Other things that may also be checked include:

• the whites of your baby's eyes
• your baby's gums
• the colour of your baby's urine or poo

Bilirubin test

If it's thought your baby has jaundice, the level of bilirubin in their blood will need to be tested.

This can be done using:

• a small device called a bilirubinometer, which shines light on to your baby's skin (it calculates the level of bilirubin by analysing how the light reflects off or is absorbed by the skin)
• a blood test of a sample of blood taken by pricking your baby's heel with a needle (the level of bilirubin in the liquid part of the blood called the serum is then measured)

In most cases, a bilirubinometer is used to check for jaundice in babies.

Blood tests are usually only necessary if your baby developed jaundice within 24 hours of birth or the reading is particularly high.

The level of bilirubin detected in your baby's blood is used to decide whether any treatment is needed.

Further tests

Further blood tests may be needed if your baby's jaundice lasts longer than 2 weeks or treatment is needed.

The blood is analysed to determine:

• the baby's blood group (this is to see if it's incompatible with the mother's)
• whether any antibodies (infection-fighting proteins) are attached to the baby's red blood cells
• the number of cells in the baby's blood
• whether there's any infection
• whether there's an enzyme deficiency

These tests help determine whether there's an underlying cause for the raised levels of bilirubin.

Treatment

Complications

Kernicterus is a rare but serious complication of untreated jaundice in babies. It's caused by excess bilirubin damaging the brain or central nervous system.

In newborn babies with very high levels of bilirubin in the blood (hyperbilirubinaemia), the bilirubin can cross the thin layer of tissue that separates the brain and blood (the blood-brain barrier).

The bilirubin can damage the brain and spinal cord, which can be life threatening.

Brain damage caused by high levels of bilirubin is also called bilirubin encephalopathy.

Your baby may be at risk of developing kernicterus if:

• they have a very high level of bilirubin in their blood
• the level of bilirubin in their blood is rising rapidly
• they don't receive any treatment

Initial symptoms of kernicterus in babies include:

• poor feeding
• irritability
• a high-pitched cry
• lethargy (sleepiness)
• brief pauses in breathing (apnoea)
• their muscles becoming unusually floppy, like a rag doll

As kernicterus progresses, additional symptoms can include fits (seizures) and muscle spasms that can cause arching of the back and neck.

Treatment for kernicterus involves using an exchange transfusion as used in the treatment of newborn jaundice.

If significant brain damage occurs before treatment, a child can develop serious and permanent problems, such as:

• cerebral palsy (a condition that affects movement and co-ordination)
• hearing loss (which can range from mild to severe)
• learning disabilities
• involuntary twitching of different parts of their body
• problems maintaining normal eye movements (people affected by kernicterus have a tendency to gaze upwards or from side to side, rather than straight ahead)
• poor development of the teeth