Your Baby’s Screening Confirmatory Testing

Confirmatory tests are also called diagnostic tests. They confirm or rule out a medical condition in an individual with concerning symptoms or an out-of-range screening result.

When following up with the baby’s healthcare provider for confirmatory testing, it may be helpful to ask the following questions:


  1. For which condition did my child have an out-of-range result?
    Newborn screening tests for a panel of conditions. However, when a child has an out-of-range screening result, it does not mean that he or she tested positive for the entire panel. Usually a child will only be out-of-range for a single condition. At the follow-up appointment, a doctor will have a copy of the baby’s newborn screening result so that confirmatory testing can be targeted towards a specific condition. This healthcare provider will be able to answer any questions about the baby’s screen result.
  2. What kind of test will the next test be, and how and when will I learn the results?
    The follow up test will depend on the condition for which the child tested positive. The evaluation may include:
    • Blood test – Some conditions found on the newborn screening panel cause certain substances to build up in a child’s blood cells. Doctors can, therefore, study a blood sample to determine if the child has one of the conditions.
    • Urine test - Some conditions found on the newborn screening panel cause a child to have elevated levels of certain substances in his or her urine. Doctors can determine if the child has one of these conditions by studying a urine sample.
    • Skin biopsy –Some conditions found on the newborn screening panel are associated with an accumulation of certain substances in a child’s skin cells. The child’s doctor may need to take a small sample of skin (called a skin biopsy) to determine if one of these conditions is present.
    • Specialized testing – Some conditions found on the newborn screening panel are associated with unique characteristics (i.e. elevated levels of certain substances in a child’s sweat, hearing loss). Doctors have specialized tests such as sweat tests and audiology tests to evaluate these features.
    • Physical evaluation – Many of the conditions have early signs or symptoms that begin shortly after birth. The doctor will do a thorough physical evaluation and may ask if the baby has any of the concerning features associated with the condition. If the baby has certain symptoms, the doctor may suggest starting immediate treatment.
    • Molecular genetic testing – If one of the tests described above suggests that a child does have a genetic condition, the doctor may use molecular genetic testing to confirm the diagnosis. This involves taking a small sample of blood.
  3. Do I need to see another doctor?
    Depending on the condition in question, a child may need to be evaluated by a medical specialist (i.e. metabolic specialist, dietician, audiologist). Your child's physician can help coordinate care with other providers or medical resources in the community.
  4. How should I prepare for the follow-up evaluation? What do I need to bring?
    • Come to the visit with a list of questions to ask your child's health care provider. This will help the child’s physician address specific concerns.
    • If the child has any concerning symptoms that could be suggestive of the out-of-range condition, write them down. This will help the doctor determine if the child needs immediate treatment or a referral to a specialist.
    • Since most of the conditions found on the newborn screening panel are inherited, the child’s doctor will probably ask questions about the family health history. It can be useful to ask relatives about what types of medical conditions occur in the family before the follow-up visit. However, do not be surprised if there is no history of these health problems in the family. Most children identified through newborn screening are born into families with no history of the condition.
  5. Should I try to find more information about the disorder? Can you tell me where to look?
    Since most children with an out-of-range screening result are healthy, many healthcare professionals do not discuss condition-specific information until confirmatory testing is completed. However, if a parent would like to find more information about the condition, the child’s doctor can recommend specific websites that are known to be accurate and trustworthy. Information about each of the conditions included in state newborn screening panels can also be found in the Find a Condition section of this website.
Depending on which type of confirmatory test was performed, it can take 1-3 weeks to get the results. Possible results include:
  • A False Positive
  • A True Positive
  • Carrier Identification

Waiting for the test result can be a very stressful time for families. It is, therefore, very important to use healthy coping methods to manage the stress, including speaking with others and searching for information. Parents may also want to ask the doctor if there any symptoms they should watch for or any precautions to take while waiting for the results.