Introduction

Jaundice is a common condition in newborn babies that causes yellowing of the skin and the whites of their eyes.

Jaundice in newborn babies up to a week old is called physiological jaundice.  Jaundice that lasts for more than two weeks is called prolonged jaundice. Both types are of jaundice are generally considered to be harmless, however:
 

• prolonged jaundice can be a sign of serious liver disease
• jaundice that develops in the first 24 hours of a baby's life requires urgent medical attention

Bilirubin

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

The liver should filter the bilirubin from the blood, and change it into a form that allows it to be passed through the gut. It is then excreted (passed out) from the body in faeces (stools). In newborn babies, the bilirubin builds up too fast for the liver to filter it all out, causing jaundice. This can occur because:
 

• newborn babies have more red blood cells than adults, and the red blood cells have a shorter lifespan
• the breakdown and removal of bilirubin is slower in newborn babies than in adults

How common is jaundice in newborn babies?

Jaundice is very common, occurring in around 60% of newborn babies during their first week of life. This figure rises to 80% in pre-term babies (babies born early). Jaundice is more common in babies who are breastfed, and around 10% of breastfed babies will still have jaundice when they are one month old.

Outlook

Many babies are jaundiced for up to two weeks following birth. You should seek medical assistance if your baby develops jaundice at a later stage because sometimes it can be a sign of a serious underlying condition, such as liver disease.

Medical attention is also necessary if:
 

• your baby is still jaundiced after two weeks
• the jaundice does not start until your baby is seven days old
• your baby’s faeces (stools) are chalky white

In cases of severe jaundice, or where it does not improve, phototherapy (light treatment) can be used to speed up the removal of bilirubin from the blood. An exchange transfusion (blood transfusion) can also be used. This replaces some of the baby’s blood with donor blood that does not contain bilirubin.

A complication, called kernicterus, can develop if the bilirubin in the blood enters the brain, leading to brain damage or death. However, this is very rare, occurring in less than one baby for every 100,000 live births.

Symptoms

Jaundice usually appears about three days after birth and disappears by the time the baby is two weeks old. In premature babies, who are more prone to jaundice, it can take five to seven days to appear and usually lasts slightly longer. It also lasts longer in babies who are breastfed.

If you baby has jaundice, their skin will look slightly yellow. It often looks like a suntan. If your baby has dark skin, you may notice the yellowing:

• 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 usually starts on the head and face, before spreading to the chest and stomach. In some babies the yellowing reaches their legs and arms.

Your baby may have other symptoms including:

•  itchy skin
• poor sucking or feeding
• sleepiness
• a high-pitched cry
• limpness (floppiness)
• dark urine instead of colourless urine
• white or creamy faeces (stools) instead of bright yellow or orange coloured faeces.

See your GP as soon as possible if you think your baby may have jaundice.

Causes

Jaundice is caused by hyperbilirubinameia (when there is too much bilirubin in the blood).  Bilirubin is a yellow substance that is produced when red blood cells, which carry oxygen around the body, are broken down.

The bilirubin is transported in the bloodstream to the liver.  The liver changes the form of the bilirubin so that it can be excreted (passed out) of the body in faeces (stools). However, if there is too much bilirubin in the blood, or if the liver cannot get rid of it, the excess bilirubin will cause jaundice.

Newborn babies

Three factors make jaundice in newborn babies very common.

• Newborn babies have a greater number of red blood cells than adults
• The red blood cells in babies have a shorter life span then those found in adults, so they are broken down and replaced at a faster rate.
• The process to break down and excrete the bilirubin is slower than it is in adults.

This explains why jaundice can occur in 60-80% of newborn babies. By the time a baby is two weeks old, they are producing less bilirubin and their liver is more effective at removing it from the body. Therefore, the jaundice usually corrects itself without causing any harm.

Breastfed babies

Babies who are breastfed are morle likely to deevlop jaundice within their first week of life compared to babies who are bottle-fed, Some possible explanations for this are described below, although the reasons are not fully clear.

• It may be because breastfed babies are fed slightly less, so they are not getting the nutrients and fluids that are necessary to help their body break down and excrete bilirubin.
• Breastfeeding may somehow cause the bilirubin that is in the intestines (part of the digestive system) to be re-absorbed back into the blood, instead of being excreted.
• It is also possible that breast milk contains an unidentified, but harmless substance that causes jaundice in newborn babies.

If you are breastfeeding your baby, there is no need to stop, even if your baby has mild symptoms of jaundice. You may wish to discuss this with your GP or midwife, who will be able to advise you about the best way that you can care for your baby.

Risk factors

The following factors may increase your baby’s chances of developing hyperbilirubinaemia:
 

• your baby is born before week 38 of the pregnancy
• you have had another child that required treatment for neonatal jaundice
• you intend to only breastfeed your baby (not bottle-feed as well)
• your baby has jaundice within 24 hours of being born

Alternative causes

In some cases, jaundice may have an alternative cause. Some of these are described below.

Metabolic liver disease, a disease that affects the function of the liver.

• An underactive thyroid gland (hypothyroidism).
• Blood group incompatibility, when the mother and baby have different blood types, and these 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.
• An inherited enzyme deficiency (enzymes are proteins that speed up and control chemical reactions in the body), such as a deficiency of glucose-6-phosphate-dehydrogenase (G-6-PD), an enzyme that helps red blood cells function.
• Gilbert’s syndrome, a genetic (inherited) liver disorder where the liver cannot properly process bilirubin.
• Crigler-Najjar syndrome, an inherited condition that adversely affects the enzyme responsible for processing bilirubin, leading to an excess build up of bilirubin.
• An obstruction or defect in the bilary system.  The bilary system is made up of the bile ducts and gall bladder, and it creates and transports bile (a fluid that is used to help digest fatty foods).
• Hepatitis, a condition that causes inflammation (swelling) of the liver, usually as a result of the hepatitis A, B, C, D, or E viruses.

Diagnosis

When your baby is born, your midwife or another healthcare professional, will check them for jaundice, although it does not usually appear for a few days. If your baby has jaundice, they may be kept in hospital for a few days for observation.

On arriving home with your baby, you should keep an eye on them.  Check their skin and the whites of their eyes in a well-lit room. Your midwife or health visitor will also check for jaundice.

To test for jaundice, gently press your fingers on the tip of your child's nose or forehead. If the pressed skin goes white, your child does not have jaundice.  If it goes yellow, your baby may have jaundice. 

You should see your GP, or midwife, if: 

• your baby is jaundiced
• your baby’s jaundice is getting worse
• your baby’s faeces (stools) are chalky white
• your baby has been jaundiced for over two weeks

Visual examination

Your GP will examine your baby to look for signs of jaundice. They will need to undress your baby and have a look at their skin under good light. They may also check:

• the whites of your baby’s eyes
• your baby’s gums
• the colour of your baby’s faeces (stools)

Bilirubin test

If the doctor thinks your baby may have jaundice,  they will need to test the level of bilirubin ( the yellow substance produced when red blood cells are broken down) in your baby's blood. This can be done in two ways, which are described below.

• A transcutaneous bilirubinometer is a small device that beams light onto your baby’s skin. By analysing how the beams of light are reflected off the skin, or absorbed by the skin, the device calculates the level of bilirubin in the blood.
• A serum bilirubin measurement can be obtained from a sample of blood, usually taken by pricking the heel of your baby’s foot with a needle. The level of bilirubin in the liquid part of the blood (the serum) is then measured.

Further tests

Some further tests may need to be carried out if your baby's jaundice lasts longer than two weeks, or if the jaundice requires treatment. The tests will help to determine whether there is another underlying cause for the hyperbilirubinaemia (raised levels of bilirubin).

Possible tests include:

• finding out the baby’s blood group by testing a sample of their blood to see if their blood group is incompatible with their mother’s
• a Coombs test, testing a sample of blood to detect antibodies (infection fighting chemicals) that may be attached to the surface of your baby’s red blood cells
• finding out the packed cell volume of your baby’s blood – this tests the amount of cells that are in the blood
• testing a sample of your baby’s blood, urine, or cerebrospinal fluid (the fluid that surrounds the brain and spinal cord) for infections
• testing for the enzyme glucose-6-phosphate dehydrogenase (G-6-PD) in a sample of your baby’s blood to see whether they have a G-6-PD deficiency
• carrying out a full blood count on a sample of your baby’s blood – this involves a number of tests to check different parts of the blood

Treatment

You should see your GP or midwife if your baby develops jaundice. They will advise you about any treatment that is needed. if your baby develops jaundice within the first week of life, treatment is not usually necessary as long as your baby is healthy. Your GP or midwife may monitor your baby by measuring the level of bilirubin in their blood.

If you are breastfeeding, you should continue to breastfeed your baby regularly, waking them up for feeds if necessary.

Jaundice usually disappears after 10 to 14 days but it may last up to three weeks in premature babies (babies born before the 37th week of the pregnancy). In babies who are breastfed, 10% will still have jaundice when they are one month old.

See your GP immediately if:

• your baby's jaundice does not disappear after two weeks
• the jaundice does not start until seven days after they are born
• your baby's faeces (stools) are chalky white

If your baby’s jaundice does not improve, or it is severe, they may be admitted to hospital and treated with:
 

• phototherapy
• an exchange transfusion

Phototherapy

Phototherapy is a treatment with light, used since the early 1970s. Phototherapy lowers the bilirubin levels in your baby's blood by photo-oxidation. Oxidation is the process of adding oxygen to change a substance (in this case, the bilirubin).

The photo-oxidation converts the bilirubin into a water-soluble substance (a substance that dissolves easily in water). This makes it easier for your baby's liver to break down and remove the bilirubin from their blood.

There are two types of phototherapy.

• Conventional phototherapy, where your baby is placed under a halogen or fluorescent lamp with their eyes covered to prevent damage to their retinas (the light-sensitive surface at the back of the eyes).
• Fibreoptic phototherapy, where your baby lies on a blanket that incorporates fibreoptic cables. Light travels through the fibreoptic cables and shines onto your baby’s back.

In both methods of phototherapy, the aim is to expose your baby’s skin to as much light as possible.

In most cases, conventional phototherapy is the first choice for treatment. However, if your baby was born prematurely, fibreoptic phototherapy may be used first.

If possible, the phototherapy will be stopped for 30 minutes every three to four hours so that you can feed your baby. If the jaundice is more severe, phototherapy will not be stopped. Instead, your baby will be fed with a tube intravenously (through a vein) or orally (through their mouth).

Your baby’s serum bilirubin level (the amount of bilirubin in their blood) will be tested every four to six hours after phototherapy has started. Once the bilirubin levels have started to fall, the serum bilirubin will be tested every 6-12 hours. The phototherapy will be stopped when the bilirubin level is low enough.

Side effects of phototherapy

It is possible for your baby to become dehydrated (when the normal water content of their body is reduced) during phototherapy. As your baby’s body expels the bilirubin, more water is lost through their skin, and more urine is produced. Your baby may need to have intravenous hydration (where water is given into a vein) if they are not able to drink a sufficient amount.

Exchange transfusion

A blood transfusion, known as an exchange transfusion, will be considered if:
 

• your baby has, or is at risk of, severe hyperbilirubinaemia (high levels of bilirubin in the blood)
• your baby has hyperbilirubinaemia and phototherapy has not worked

Exchange transfusions have been used since the 1950s and are very effective. The transfusion normally takes place through an intravenous catheter (a tube that is inserted into a vein).

During an exchange transfusion, some of your baby’s blood will be removed and replaced with blood from a suitable, matching donor (someone with the same blood group). As the new blood will not contain bilirubin, the overall level of bilirubin in your baby’s blood will fall.

Side effects of an exchange transfusion

Exchange transfusions are generally considered to be safe and effective, but some side effects are possible including:
 

• thrombocytopaenia, an abnormal drop in the number of platelets in the blood (platelets are cells that help the blood to clot)
• hypocalcaemia, when the level of calcium in the body falls to a low level
• hypotension (low blood pressure)
• a problem with the catheter (the tube used during the transfusion)
• venous thrombosis, when a blood clot develops in a vein
• hypokalaemia, an abnormally low level of potassium in the blood
• hypoglycaemia, an abnormally low level of sugar (glucose) in the blood
• bradycardia, an abnormally slow heart rate
• apnoea, a temporary interruption in breathing as the throat muscles relax and cause a total blockage of the throat's airway
• severe bleeding
• a blood clotting problem
  

These possible side effects do not outweigh the benefit of having an exchange transfusion. Throughout the process, healthcare professionals will be there to monitor your baby and treat any complications that arise.

Other treatments

If jaundice is caused by something else, such as an infection, this will be treated as necessary. This may mean using surgery or medication.

If the jaundice is caused by Rhesus disease (when the mother has rhesus-negative blood and the baby has rhesus-positive blood), intravenous immunoglobulin (IVIG) may be used.

The immunoglobulin is a solution of antibodies (proteins that are produced by the body to destroy disease-carrying organisms) from healthy donors. It is injected into a vein (intravenous).

IVIG will only be used if phototherapy alone has not worked, and the level of bilirubin in the blood is continuing to rise at a rapid hourly rate.

Complications

Kernicterus is a complication of untreated hyperbilirubinaemia (high levels of bilirubin in the blood). Bilirubin is the yellow substance produced when red blood cells are broken down.

In newborn babies with hyperbilirubinaemia, the bilirubin can cross the membrane (thin layer of tissue) that separates the brain and the blood. The bilirubin causes yellow staining of the brain, and can damage the brain and spinal cord. This may result in short-term or long-term brain damage or even death.

Kernicterus is the term used to describe any yellow staining of the brain, or damage to the brain that is caused by a high level of bilirubin. 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

Symptoms

Short-term symptoms of kernicterus include:
 

• lethargy (lack of energy)
• irritability
• abnormal muscle tone (increased muscle tone could make your baby appear stiff or rigid; decreased muscle tone will make them appear floppy)
• difficulty maintaining their posture
• apnoea (a temporary interruption in their breathing)
• convulsions (fits or seizures)
   

Long-term symptoms of kernicterus include:
 

• athetoid cerebral palsy (a condition that affects the brain and nervous system) that causes both increased and decreased muscle tone, and affects your baby’s movement and coordination
• hearing loss
• visual problems
• dental problems

Fortunately, kernicterus is very rare. For example, research carried out with the assistance of the Royal College of Paediatrics and Childcare identified 13 cases of bilirubin encephalopathy (brain damage caused by high levels of blirubin) in the UK over a two-year period. This works out at less than one case for every 100,000 live births.

Out of the 13 cases of bilirubin encephalopathy that were identified in the UK, and one case that was identified in the Republic of Ireland, three babies died. Of those babies followed up after 12 months, six had permanent complications, such as hearing loss or cerebral palsy.