Jaundice in newborns - Diagnosing jaundice in newborn babies

Your baby will be checked for jaundice within 72 hours of being born, but you should keep an eye out for signs of the condition after you return home because it can sometimes take up to a week to appear.

When you are at home with your baby, you should 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 stools (faeces). Your baby may have jaundice if their urine is yellow (a newborn baby's urine should be colourless) or their stools are pale.

You should 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 determine whether any treatment will be necessary.

Read more about the symptoms of jaundice in babies.

Visual examination

A visual examination of your baby will be carried out to look for signs of jaundice. Your baby will 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 stools or urine

Bilirubin test

If it's thought that your baby may have jaundice, the level of bilirubin (the yellow substance produced when red blood cells are broken down) in your baby’s blood will need to be tested. This can be done using:

a small device called a bilirubinometer, which 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 blood test of a sample of blood usually obtained by pricking your baby's heel with a needle. The level of bilirubin in the liquid part of the blood (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 bilirubinometer reading is particularly high.

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

Read more about treating jaundice in babies

Further tests

Some further tests may need to be carried out if your baby's jaundice lasts longer than two weeks, or if treatment is required. The tests will help to determine whether there is another underlying cause for the 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, which involves testing a sample of blood to detect antibodies (infection-fighting proteins) 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 number of cells 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 several tests to check different parts of the blood for a number of other possible problems

Antibodies: Antibodies are your body's natural defence against any foreign antigens that enter your blood. An antibody is a protein produced by the body to neutralise or destroy disease-carrying organisms and toxins.
Blood: Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.
Enzymes: Enzymes are proteins that speed-up and control chemical reactions, such as digestion, in the body.
Liver: The liver is the largest organ in the body. Its main jobs are to secrete bile (to help digestion), detoxify the blood and change food into energy.