Every newborn in Australia is offered a blood test to check for the presence of particular metabolic or genetic disorders, including phenylketonuria (PKU), hypothyroidism and cystic fibrosis. The benefit of this test is early detection – many complications of these disorders can be avoided with prompt treatment.
Usually, a blood sample is taken between 48 and 72 hours after birth. The blood is taken by pricking the baby’s heel and placing a few drops of blood onto a piece of absorbent paper. Once dried, the blood sample is examined in a laboratory. The absorbent paper (Guthrie Card) with the blood may be stored. In NSW and Victoria, the Guthrie Cards are currently stored indefinitely.
A range of disorders
Some of the disorders that can be detected by newborn screening include:
- Phenylketonuria (PKU) – a disorder where the liver does not produce enough of a particular enzyme and cannot metabolise (breakdown) phenylalanine – one of the 20 amino acid building blocks of protein. If untreated, PKU can lead to brain damage.
- Hypothyroidism – the thyroid gland helps regulate metabolism. A lack of thyroid hormone can cause severe intellectual disability and growth problems. Early detection and treatment enables children to be healthy.
- Cystic fibrosis – organs such as the lungs and pancreas secrete an abnormal mucus that clogs the affected organs and stops them working properly.
- Other rare metabolic disorders – there are many other rare metabolic disorders caused by faults in the breakdown of proteins and fat. Early detection and treatment, before they become sick, results in a better outcome for babies.
How testing is performed
Levels of biochemical markers for the above disorders are measured in the blood spots. The only genetic test performed is on a small number of samples (about one per cent) that have an increased level of the marker for cystic fibrosis.
A positive test result
Sometimes, your baby will need a second blood test. This doesn’t automatically mean that your baby has a disorder. It may simply mean that the first test didn’t return a clear enough result. In most cases, the baby is healthy. Sometimes, the test result indicates that further tests are required. If your baby is diagnosed with one of the above disorders, treatment will start immediately. For example, a newborn with phenylketonuria needs a diet low in phenylalanine. Be guided by your doctor.
Support is available
The Genetic Support Network of Victoria (GSNV) aims to ensure that all people with a genetic disorder in Victoria have appropriate and accurate information and support to enable them to manage the challenges to their health and wellbeing. The GSNV facilitates an exchange of information, resources and assistance.
Where to get help
- Your doctor
- Paediatrician
- Genetic Health Services Victoria, Royal Children’s Hospital Tel. (03) 8341 6201
- Genetic Support Network of Victoria Tel. (03) 8341 6315
Things to remember
- Every newborn in Australia is offered a blood test to check for the presence of particular metabolic or genetic disorders, including phenylketonuria (PKU), hypothyroidism and cystic fibrosis.
- The blood is taken by pricking the baby’s heel.
- The vast majority of babies will have a normal screening test result.
- Occasionally a repeat test is needed. The results will usually be in the normal range.
- If a baby is confirmed to have one of these conditions, the parents will be contacted to arrange prompt treatment for their baby.
You might also be interested in:
Cystic fibrosis.
Genetic services in Victoria.
Metabolism explained.
Phenylketonuria (PKU).
Thyroid disorders - hypothyroidism.
Want to know more?
Go to More information for support groups, related links and references.
| 
Home >
Fact sheets by category >
Healthy living >
Pregnancy >
General >
Newborn screening.
