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Newborn Screening Process

This page features information about newborn screening (NBS) and what happens during each step in the process, including the 3 tests that are part of the screening process: blood spot screening, pulse oximetry screening, and hearing screening.

Follow the links below for answers to commonly asked questions about NBS.

When Does Newborn Screening Happen?

The timing of newborn screening (NBS) is very important. Babies need screening during the first few days of life, because some of the conditions found by screening require treatment or intervention right away.

NBS happens after birth, usually when your baby is between 24 and 48 hours (1 and 2 days) old. If a baby is tested before 24 hours, they may need to be retested.

Some babies who have had treatments such as transfusions or dialysis may be tested later or may need further testing after their blood has returned to normal. In addition, babies who are born too early, or who receive nutrients or medicines before screening, may need further testing.

There are two models that states use to screen all newborns: the one-screen model or the two-screen model.

  • Most states use the one-screen model. In this model, babies are screened only once when they are 24 to 48 hours old. This one screen looks for all conditions on the state’s newborn screening panel.
  • Thirteen states use the two-screen model. In this model, all babies are screened at 24 to 48 hours old and screened again at 1 to 2 weeks old. The second screen usually happens in a health care provider’s office as part of a well baby visit.
  • States choose the one-screen model or the two-screen model based on many factors. These factors can include historical practice in the state or the testing cut-offs (guidelines to decide if a baby needs follow up) the state uses. In either model, all babies are screened for all of the conditions that their state requires.
  • Whether you live in a one-screen or two-screen state, your baby may need additional screening and follow up based on their newborn screening results.

To learn more about the differences in NBS across different states, visit the State pages.

Where Does NBS Happen?

All babies need NBS, regardless of where they are born.

If your baby is born at a hospital, screening will happen before you take your baby home. Usually, a health care provider performs NBS in your room or a newborn/nursery area.

If your baby has an out-of-hospital birth, screening can happen outside of the hospital like at your birth center or home. Many midwives are trained to complete NBS. 

If you are planning an out-of-hospital birth, talk to your midwife about NBS before your baby is born. If your midwife cannot perform NBS, make other arrangements. Your baby’s health care provider can help arrange screening by another midwife, a hospital, clinic, or local health department. It is important that you make a plan so your baby completes screening near the recommended age.

How Does NBS Happen?

Newborn screening has three different 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

Blood Spot Screening

Blood spot screening (sometimes called the “heel stick” or “24-hour test”) uses a few drops of blood from your baby’s heel to determine if your baby might have one of many serious conditions. Even though some health care providers still refer to blood spot screening as the “PKU test,” this term is no longer accurate because NBS now checks for many conditions.

Following is a step-by-step guide explaining how blood spot screening happens:

  • Between 24 and 48 hours after birth, a health care provider will tell you that it is time for your newborn’s blood spot screening.
  • Your baby can stay swaddled during blood spot screening.
  • To make the process easier, the health care provider will gently warm your baby’s foot to increase blood flow.
  • The health care provider will then make a quick pinprick on your baby’s heel. Your baby may feel the prick and start to cry, but it will be over very quickly and will not leave a mark.
  • The health care provider will collect a few small drops of blood from your baby’s heel, then drop them onto small circles on a special card.
    • The part of the card with the circles contains a type of paper called filter paper. This paper absorbs the blood drops.
    • The other part of the card has information about your baby. This information tells whose blood is on the card and how to reach you and your baby’s health care provider.
  • Once the blood spots have dried, the card is sent off to a laboratory. There, the staff runs laboratory tests looking for signs of certain serious conditions. Each state has its own newborn screening panel, which is a list of the conditions that the state checks during NBS. To see the newborn screening panel for your state, visit the State pages.

Results from blood spot screening are usually ready in about five to seven days. The public health laboratory sends your baby’s results to your baby’s health care provider, not straight to you. If the result suggests the presence of a condition, then either the health care provider or the state NBS program will contact you.

Be sure to ask about your baby’s results at your baby’s first or second well-child visit. It is important to ask about your baby’s NBS results—do not assume that no news means that the results are in-range.

To learn more about blood spot screening results, visit the Newborn Screening Results and Follow-Up page.

Pulse Oximetry Screening

Pulse oximetry screening uses a sensor to determine if your baby might have certain heart conditions called critical congenital heart disease (CCHD).

CCHD is a group of serious heart conditions present at birth. Children with CCHD have any of a wide range of heart problems that arise when parts of the heart do not form correctly.

In some forms of CCHD, the heart has trouble delivering oxygen from the lungs to the rest of the body. Babies with these forms of CCHD have low levels of oxygen in their blood. Measuring your baby’s blood oxygen level can help see if your baby needs urgent heart treatment. 

Following is a step-by-step guide explaining how pulse oximetry screening happens:

  • Between 24 and 48 hours after birth, a health care provider will tell you that it is time for your newborn’s pulse oximetry screening.
  • The health care provider will place a small wrap on your baby’s skin, usually around the right hand or wrist and on either foot. One side of the wrap has a light, and the other has a sensor.
  • The health care provider will connect the wrap to a monitor that uses the sensor’s reading to calculate how much oxygen is in your baby’s blood. Using the numbers on this monitor, the health care provider can tell whether your baby might have CCHD.
  • Babies who do not pass pulse oximetry screening the first time may repeat it or may need further testing.

Results from pulse oximetry screening are ready as soon as the screening is done.

If your baby does not pass pulse oximetry screening, a health care provider may recommend more testing to see if your baby’s heart and lungs are working well. This testing can involve an echocardiogram, electrocardiogram, and/or chest X-ray, which is usually done right away.

Your baby’s health care provider will help decide what test(s) your baby needs.

To learn more about pulse oximetry results, visit the Newborn Screening Results and Follow-Up page.

Hearing Screening

Newborn hearing screening uses earbuds or earphones to check your baby’s hearing.

Babies do not usually start talking until they are about 1 year old, but language begins developing at birth. Babies learn sounds, speech, and language by hearing people speaking around and to them during the first months of life.

A child who has even a mild hearing loss may be slow to learn words and how to communicate if not helped early. Newborn hearing screening is important because it finds children that may need help as early in their lives as possible.

Following is a step-by-step guide explaining how newborn hearing screening happens:

  • Hearing screening usually happens any time after your baby is 12 hours old. Around or after this time, a health care provider will tell you that it is time for your newborn’s hearing screening.
  • Hearing screening works best when your baby is calm and in a quiet room. You may be asked to hold your baby during screening, or your baby may stay swaddled.
  • There are two types of hearing screening. Your baby might have one or both types. Both types work similarly and are quick and safe.
    • Otoacoustic emissions (often called “OAE”): In this screening, a health care provider places a small ear bud in each of your baby’s ears. The ear buds play soft sounds for your baby. The ear buds are connected to a computer that measures how the ear responds to the soft sounds. If your baby’s ears are working as they should, the computer will detect a response. If your baby is deaf or hard of hearing, the computer will not detect a response.
    • Automated auditory brainstem response (often called “AABR”): In this screening, a health care provider places earphones over your baby’s ears and small sensors that look like band-aids on your baby’s head and neck. The earphones play soft sounds for your baby. The sensors measure how your baby’s ears and brain respond to the sounds and then send this information to a computer. If your baby can hear typically, the computer records a response to the sounds. If your baby is deaf or hard of hearing, the computer records either a very small response or no response at all.
  • Your baby may not pass screening if your baby is deaf or hard of hearing in one or both ears, if there is fluid in the ear, or if there is too much noise during screening (for example, from movement or crying).

Results from hearing screening are ready as soon as the screening is done.

If your baby does not pass the hearing screening, resulting in a “fail,” you will be referred to a specialist for more evaluation and testing of your baby’s hearing. This second check usually happens one to two weeks after the first screening.

To learn about understanding your baby’s hearing screening results, visit the Newborn Screening Results and Follow-Up page.

You can also learn more about deafness and hearing loss at:

Is NBS the Same for All Babies in the U.S.?

No.

Even though every state in the U.S. requires NBS, each state manages its own NBS program. This means that NBS can be a little different in each state.

For example, some states may give parents different options during screening, have different NBS costs, or look for different conditions during screening. It is important to be familiar with how NBS works in your state.

To learn about NBS in your state, visit the State pages.

Parent Options During Screening

States give parents options during NBS. Examples of choices that differ by state include the following:

  • Whether and how to refuse NBS—All states require NBS, but most states let parents refuse screening for their baby. Accepted reasons for refusal depend on the laws in a state. For example, some states only let parents refuse NBS for religious reasons. Other states let parents refuse for any reason. A couple of states do not allow parents to refuse NBS at all.
  • What happens with your newborn’s blood spots after NBS—Some states give parents choices about what happens to their baby’s dried blood spots after screening is complete. For example, some states let parents choose whether the blood sample is stored, destroyed, or used for research studies.

You can find out about parent options in your state by contacting your state’s newborn screening program. Contact information for programs in each state is available on the State pages.

Differences in the Newborn Screening Panel

The group of conditions that a state has chosen to detect with newborn blood spot screening is called its newborn screening panel. In the U.S., each state decides which conditions to include on its newborn screening panel. This means that babies in different states may be screened for slightly different panels of conditions.

States consider many things (PDF - 111 KB) (PDF – 111 KB) when deciding which conditions belong on their newborn screening panels. For example, all core conditions on state newborn screening panels:

  • Have a low-cost screen
  • Cannot be found just by looking at a baby
  • Are serious and, without treatment, cause serious health problems early in life
  • Have health care providers with the right expertise to diagnose, treat, and care for babies with the conditions
  • Have an effective treatment

To help states decide which conditions to include on their newborn screening panels, the U.S. Secretary of Health and Human Services provides a list of conditions recommended for newborn screening. This list is called the Recommended Uniform Screening Panel (RUSP).

To learn more about the RUSP, visit the Recommended Uniform Screening Panel page.

Before Newborn Screening: Questions to Ask

Many parents have questions about NBS. Following is a list of questions that you may want to ask your health care provider or your baby’s health care provider before your baby’s birth, before your baby’s screening, or while your baby is being screened.

  • Will I need to ask for my baby to be screened?
  • When does NBS happen?
  • Can I be with my baby during screening?
  • How are the costs of newborn screening covered?
  • For what conditions will my baby be screened?
  • What options do I have for NBS?
  • How long will it take to get my baby’s results?
  • How will I get my baby’s results?
  • When will the results be in my baby’s medical chart?
  • What will happen if my baby’s tests are out-of-range?
  • Who can I contact if I have more questions?
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