Newborn birth procedures: The Guthrie Test

In the second day of your baby's life, it suddenly feels as though people are constantly wanting to do tests and evaluations on them. First they whisk your baby away from you to do a hearing test, then the baby cries as they unwrap it to check every little detail and then the midwife comes in with a pamphlet and a piece of card wanting to prick your baby's heel. What the hell?

The Guthrie Test (or heel prick test)
This test has been around for over 35 years, because of this it has become so much part of the landscape of postnatal care that explaining it to parents is often overlooked. One study has shown that the majority of parents were not aware of the importance of the test. Fortunately this does not seem to lead to many parents rejecting the test but does mean that parents may be unprepared if they are recalled for another test. 

What the test does
The newborn screening test is designed to pick up if your child has a genetic condition that is helped by early diagnosis. It does not test for all genetic conditions and the exact conditions tested for varies from country to country and from state to state. The conditions tested for are generally conditions to do with deficiencies of a hormone or problems with ways that the body breaks down food (or milk/formula in a baby's case). Left untreated this results in toxic effects on the brain leading to mental retardation and in some cases death. Early diagnosis and treatment, which may mean medication or diet changes, can minimise and in some cases totally prevent these effects.
Cystic fibrosis, a condition where there are sticky secretions into the lungs, is also often tested for as early diagnosis and treatment improves the overall lifespan. 

Why they test everyone
The babies with these conditions will appear to be well and are generally indistinguishable from other healthy babies. By the time they become unwell, the condition will have already started to cause damage to their bodies. This damage can generally not be reversed. By testing them early, they can be treated before they become sick and be given their best chance at remaining healthy for as long as possible.
Parents of children with these conditions are also usually healthy and are often from long lines of healthy families where nobody has had these conditions. That is because these conditions are recessive genetic conditions so both parents need to carry a change in their genes for a baby to become sick. People who only have one change are healthy and unaffected by the change. Since these changes are rare, the chance of meeting someone else who has the same change is low and may not have happened to anyone else in the family.

What it means if they recall you
It usually means there was something wrong with the test or the result was unclear. As the conditions being tested for are so serious it is considered better for a baby to have to be retested, even though that is worrying for the parent, than it is to miss a baby that has the condition. 
Sometimes, such as in cystic fibrosis it will mean that your baby is a carrier for the condition but will not actually develop the condition themselves.
Sometimes, of course, your baby will have the disorder and for that reason it is important to have your baby retested quickly.

I'm worried about the fact its a genetic test
Although the test is genetic, it is only looking at the genes that would indicate that your baby has one of the conditions being tested for. Other things in your baby's genes, including risks for other health conditions and issues such as paternity are not examined by this test.
To prevent your babies genetic information from being misused the tests are only kept for a short period of time (in Western Australia 2 years through to 18 years in New South Wales).
The tests are not allowed to be used for any other purpose without the consent of the parents or the baby (when grown) or a legally binding order. Tests are only used for legal purposes for forensic reasons such as identifying a dead person and even then parents consent is required before the tests can be used.


Popular Posts