Newborn screening is a blood test that is offered to every newborn in Australia. The test is used to detect certain rare, genetic conditions and disorders of the metabolism.
Early diagnosis can make a big difference to the life of the baby and many possible complications can be avoided with prompt treatment.
Why are newborns screened?
Newborn screening is a free (public health funded) blood test that is used in the early identification of certain conditions in newborns. These conditions are serious and can be life threatening.
The Human Genetic Society of Australasia (HGSA) recommends that newborn screening be performed if there is:
- benefit for the baby from early diagnosis;
- benefit that is reasonably balanced against financial and other costs;
- a reliable test suitable for newborn screening;
- a satisfactory system in operation to deal with diagnostic testing, counselling, treatment and follow-up for patients identified by the test.
In Australia, all babies are tested if their parents agree, even if the baby does not show any signs of having the conditions for which they are being screened.
What conditions are screened?
There are some differences as to which conditions are tested for in different States and Territories. While about 30 conditions are tested for, the most common are:
- Phenylketonuria (PKU), in which the liver does not produce enough of a particular enzyme and can cause intellectual disability if untreated;
- Hypothyroidism, in which not enough thyroid hormone is produced and can cause intellectual disability and growth problems if untreated;
- Cystic fibrosis (CF), an untreatable but manageable condition which causes the lungs and gastrointestinal system to produce an abnormal mucus that clogs the affected organs and stops them from working properly; and
- Galactosaemia, a rare disorder caused by the build-up of galactose (a sugar in milk) in the blood, and causes problems such as poor growth, liver disease and intellectual disability or death if untreated.
Conditions that are tested for in newborn screening can be managed or treated. For example, prompt treatment of galactosaemia with special milk can completely prevent the illness.
Additional conditions may only be tested for where appropriate, such as when there are clinical signs or a family history of the condition. Should this apply, additional consent and samples will be required for testing.
The screening process
Verbal agreement of the parents is required before newborn screening can take place. Newborn screening services across the country have information pamphlets for parents to consider before consent to perform the test is sought. This provides parents with the information needed to make an informed decision. If parents have any concerns about the process, there is also opportunity to discuss these with the services involved.
Following verbal agreement from the parents, the baby’s blood is collected by a heel-prick 48 to 72 hours after birth, generally at the hospital, or by a home visit. The collected blood is dried onto absorbent paper (a Guthrie Card), and once dried, is tested for a range of conditions. Cards are stored securely by the newborn screening laboratory for varying periods according to the relevant State or Territory policy.
Receiving a positive result
All the conditions that are tested for in the newborn screening bloodspot test are for rare disorders. In most cases, the test results are normal.
Parents are contacted if there are concerns about the result and a second blood test may be needed. This does not automatically mean that the newborn has a condition. Usually, it is because the first did not give a clear result.
If a newborn is diagnosed with a particular condition, parents are notified through their doctor or midwife. Appropriate information and support will be provided. Follow up may involve additional testing and will include explaining what the diagnosis means for the newborn, condition management and/or treatment options.
Doctors, midwives and specialists such as a paediatrician can help parents better understand the process of newborn screening and provide accurate information and support.
State and Territory screening services are useful points of contact and can provide information on services available in the local region, as well as helpful factsheets and resources.