Once upon a time, when a baby was born, it might be months or years before parents could learn about a serious condition the child had. That all changed in the 1960s with the introduction of newborn screening.
Newborn screening involves the use of blood tests to look for a variety of different conditions only a few days after babies are born.
This year, Newborn Screening Awareness Month occurs in September exactly 50 years after the first research paper describing newborn screening was published.
That paper, published in 1963 by Dr. Robert Guthrie and his colleague, used a test to look for a condition called phenylketonuria. Phenylketonuria is a rare genetic metabolic disorder in which a person cannot break down a specific amino acid.
This kind of disorder may have been difficult to identify through symptoms alone before the use of a newborn test that allowed doctors to catch it within the first week of a baby's life.
By catching it early, this disorder — which can cause intellectual and developmental disabilities later on — could be caught and treated before a child suffered any negative long-term effects from the condition.
How Does Newborn Screening Work?
"A screening test is designed to pick up diseases or problems in the absence of symptoms and early in their course — often intervention can be life saving," said Tracie Newman, MD, a pediatrician with Sanford Health in Fargo, North Dakota.
"Tests vary by state, but typically there is a blood test to screen for metabolic and genetic conditions," she said. "Every baby also undergoes a hearing screen, and many places are now performing congenital heart disease screens as well."
Newborn screenings are a standard part of hospital procedures and occur regardless of whether the parents have heath insurance. "All of these are important for infant health and well-being," Dr. Newman said.
The forms parents sign when the mother is admitted to the hospital for delivery include permission to conduct the tests. All states require some level of newborn screening, though parents can opt out for religious reasons in some states.
Babies born outside of a hospital should have their screenings conducted by either a birth attendant who is qualified to take the blood sample or by a clinic the parents take the child to within the first few days after birth.
Currently, nearly all states as well as Puerto Rico use newborn screening to look for 29 different conditions. In addition, 10 states actually look for more than 50 different conditions.
These screenings are done using the blood obtained during a newborn's heel prick in the day or two after birth. This blood sample is sent off for a lab to screen for the different conditions.
The introduction of newborn screening tests helps identify approximately 12,500 babies every year who have a disorder which can then be treated.
That's approximately one out of every 300 babies whose conditions are caught and treated immediately rather than waiting until symptoms and later tests might find the condition.
To ensure that a positive test truly is positive for a particular condition, some states require a second blood test during a baby's second week of life.
Another test used in various states looks for the concentration of oxygen in a baby's blood, though it does not require a blood sample to be conducted. The results of this screening can help identify babies who have a heart condition requiring immediate attention.
The cost of newborn screening and how that cost is covered varies by states. Some states collect fees for screenings, sometimes insurance plans pick up the costs, and sometimes other state programs pay for the screenings.
What Kind of Disorders Are Doctors Looking for?
The 29 conditions that are screened in all states were listed by the American College of Medical Genetics in a set of guidelines published in 2002.
The organization also suggested another 26 conditions that can be tested in a second panel, and these two sets together are called the Recommended Uniform Screening Panel.
Most of the conditions are not ones that ordinary individuals would have heard of. Many are genetic disorders that can only be confirmed through a blood test.
The disorders are classified according to four major categories: metabolic disorders, endocrine disorders, hemoglobin disorders and then other disorders.
The metabolic disorders include three subtypes. One is conditions such as phenylketonuria, in which a person cannot process certain amino acids.
The other two are fatty acid oxidation disorders and organic acid conditions. Fatty acid oxidation disorders mean the body cannot produce or use an enzyme that is needed to handle fatty acids in the body.
Organic acid conditions involve the body overproducing organic acids, which can affect multiple organ systems when the disorder prevents the body from handling normal amino acid metabolism.
The most commonly recognized screened condition included in the standard panel of newborn screening tests is cystic fibrosis, a chronic lung disease.
The only conditions that can be considered for testing in newborn screening must be ones that meet three criteria.
The condition must be able to be identified within a day or two of being born, before a doctor's exam which would ordinarily reveal the disorder.
The condition must already have a test for the disorder that has a high enough level of accuracy. Finally, the condition must be treatable in some form so that early detection and intervention can lead to a benefit.
What Happens After the Test?
Usually, parents are not contacted about the newborn screening results unless their child tests positive for a condition.
However, a positive test does not necessarily mean the child definitely has that medical condition. Therefore, these babies undergo follow-up testing to determine whether the disorder is actually present for the child.
Some children may have received a "false positive" test result. This means the test came back at positive, but that it was not accurate. False positives are the reasons that a confirmation secondary test should be completed.
Other children may test positive as being "carriers" for a condition. Being a carrier means the child might have inherited the genetic trait for a disorder, but the child will not show symptoms of it.
If a child does have one of the medical conditions screened for, the next steps will depend on what the condition is. Either the family's pediatrician or family doctor or else the state screening program will provide parents with instructions about the next steps.
Information about the specific disorders and frequently asked questions by parents can be found at the website Babysfirsttest.org.