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About Newborn Screening

What Is Newborn Screening and Why Is It Needed?

Newborn screening (NBS) is a process that involves:

  1. Checking (screening) babies for certain serious conditions
  2. Finding those few who might have one of the conditions
  3. Helping to connect babies with the early care, treatment, and/or intervention they need to give them the best chance at a healthy life

Newborn screening is important and all babies need it. Health care providers cannot always tell if newborns have a serious health condition just by looking at them.

Many babies born with a condition have no family history of it and show no signs of it at birth. In fact, most look healthy and even have normal Apgar scores.

Newborn screening is often the only way to detect these conditions before symptoms begin. Early detection makes sure that babies who need it receive care, treatment, or intervention as early as possible, when it can work best.

Because NBS can be the only way to tell if a newborn has certain conditions, it is mandated (required) by state law in the United States (U.S.). This means that your baby will have NBS unless you refuse screening.

Each state has its own legally required list of conditions that are screened. To learn about NBS in your state, visit the State pages.

History of Newborn Screening

Newborn screening has been part of U.S. health care for more than 50 years. Many new and expecting parents in the U.S. today received an early form of NBS back when they were born!

Newborn screening began in the 1960s when Dr. Robert Guthrie developed a blood test for phenylketonuria (PKU). PKU is a serious health condition that causes brain damage if not treated very early in life.

Before the blood test existed, most children with PKU were not diagnosed until after they had brain damage. That was too late for treatment to be helpful. 

Dr. Guthrie’s blood test allowed diagnosis shortly after birth. Earlier diagnoses allowed for earlier treatment, which prevented brain damage and other serious problems for many babies with PKU.

PKU was the first condition identified by NBS, so some people still refer to all NBS as the “PKU test.” However, this term is not accurate. Today, NBS can detect PKU, many other treatable health conditions, some heart disorders, and the ability to hear, too.

What Does ‘Screening’ Mean?

The term ‘screening’ refers to checking people who appear healthy (people with no signs or symptoms) for a specific condition. Screening sorts people into two groups:

  • People unlikely to have the condition. Most people fall into this group. Members of this group do not need more testing. Their chance of having the condition, also called their risk for the condition, is low.
  • People more likely to have (or who might have) the condition. Fewer people fall into this group. Members of this group need more testing to tell for sure if they have the condition. Their chance of having the condition, also called their risk for the condition, is higher than that for people in the first group.

Common examples of health screening are a mammogram (for breast cancer), colonoscopy (for colon cancer), and Pap smear (for cervical cancer). These screens do not tell for sure if someone has breast, colon, or cervical cancer—only that they might have it and need more tests to know for sure. Screening helps people with these conditions to find out and get treatment early, when treatment usually works best.

Similarly, NBS checks a baby for certain conditions present at birth that benefit from early treatment or intervention. Newborn screening consists of three parts:

  1. Blood spot screening, which determines if a baby might have one of many serious conditions
  2. Pulse oximetry screening, which determines if a newborn might have certain heart conditions
  3. Hearing screening, which determines if a newborn might be deaf or hard of hearing

Together, the three parts of NBS help you and your baby’s health care provider detect serious conditions. This makes sure that babies can receive any recommended care, treatment, or intervention as early as possible, when it is most effective.

Are Screening and Diagnostic Testing the Same?

No, but they are related.

Screening checks whether you might have a condition. Newborn screening cannot determine whether your baby actually has that condition—only if they are more or less likely to have it.

In contrast, diagnostic testing tells whether your baby actually has a condition.

If screening suggests your baby might have a condition, you will be contacted to schedule follow-up testing. Follow-up testing often includes a diagnostic test to determine whether your baby has the condition or not. 

You may need to complete follow-up testing right away to know if your baby needs treatment or intervention. You should follow your health care provider’s directions about timing and what kind of diagnostic testing your baby needs.

Visit the Newborn Screening Results and Follow-Up page for more information on screening results and follow-up testing.

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