Common Test Done on Newborns Questioned
More than four million babies born in the U.S. every year are given a routine "heel-stick" blood test in the hospital to check for dozens of disorders.
About 4,000 infants will be diagnosed with a condition, according to the American Academy of Pediatrics.
Now, a study in the Journal of the American Medical Association finds that the test isn't an effective screening tool for a leading cause of hearing loss in children.
On "The Early Show," CBS News Medical Correspondent Dr. Jennifer Ashton explained the study found the "heel-stick" test may not catch some cytomegolovirus (CMV) infections.
Special Section: Dr. Jennifer Ashton
"(The infection is) very, very common and, in its early stages, it can be treated supportively with an antiviral medication. If not treated, it can go on to cause hearing loss and deafness. And obviously in a newborn, in a child, you don't want them to have a hearing problem, because hearing has a very serious impact on speech development."
The "heel-stick" test is done on a small blood sample prick from the infant's heel, which very similar to a diabetic blood sugar test. However, according to researchers, the test is not suitable for mass tests on newborns anymore.
Ashton said, "For a test to be accurate, you want it to be positive or detect the disease about 95 percent of the time," she said. "What they found in studying this CMV 'heel-stick' blood test is it only detected about 30 percent or 40 percent of CMV infections, so it's not a great test."
Ashton said there are other saliva tests that could detect this infection more effectively, but they're more labor intensive.
Ashton said there isn't any national standard for testing babies in the hospital. She said most of the testing gets done on a newborn after about 24 hours of life.
She said, "(Testing) does vary state to state, and in general, what the pediatricians are testing for are certain genetically inherited metabolic, hormonal, functional disorders that ideally have both accuracy in terms of the test, as well as an effective treatment."
She said hospitals perform 29 core blood tests on the newborn, in addition to a direct hearing test, and then some states do an additional 25 tests for secondary disorders.
But how can you make sure your newborn gets the best standard of tests?
Ashton suggested pregnant women speak to a pediatrician prior to giving birth about the tests performed in the hospital.
She said, "If you have certainly a family history of a genetic disorder, or if you have another child who's been impacted with a genetic disorder, or, if, in general, you just have other reasons to be concerned, you want to talk to the pediatrician about that and find out what testing can be done in the hospital in that neonatal period."
Ashton said parents can't afford to wait on tests following the birth of their child.
"(In some cases) the earlier intervention and treatment, the better, (such as) certain things like PKU (phenylketonuria), which some people may know about is a metabolic disorder that can have a serious impact on nutritional status and brain development. So some things you want to intervene right away."