Newborn jaundice : Diagnosis

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

But you should keep an eye out for the 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.

Read more about treating jaundice in babies.

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.