Newborn Screening for CF

Newborn screening (NBS) is a program run by each state to identify babies born with certain health conditions, including cystic fibrosis. Although a sweat test should ultimately be done to rule out or confirm a CF diagnosis, NBS can help you and your health care providers take immediate steps to keep your child as healthy as possible.

5 min read
In this article
  • Diagnosing cystic fibrosis early enables CF health care providers to help parents learn ways to keep their child as healthy as possible and delay or prevent serious, lifelong health problems related to CF. 
  • Newborn screening is done during the first few days of a baby's life — using only a few drops of blood from a heel prick.
  • A positive newborn screening result does not mean your baby has CF, only it’s possible that they have CF and further testing through a sweat test is required. 

Diagnosing CF Early Is Important

Newborn screening (NBS) for cystic fibrosis is done in the first few days after birth. By diagnosing CF early, CF health care providers can start medicines for CF as early as possible and help you learn ways to keep your child as healthy as possible. This can help delay or prevent serious, lifelong health problems related to CF. 

Research shows that children who receive CF care early in life have better nutrition and are healthier than those who are diagnosed later. Cystic fibrosis can affect people of every race and ethnicity, and all children should undergo newborn screening as well as follow-up sweat testing at a CF Foundation-accredited care center after a positive newborn screen. Early diagnosis and treatment can: 

  • Improve growth.
  • Help keep lungs healthy.
  • Add years to life.

How Is Newborn Screening Done?

Newborn screening is done during the first few days of your baby's life — usually by a health care provider in the hospital. A few drops of blood from a heel prick are placed on a special card, called a Guthrie card. 

This card with your baby's information is mailed to a special state laboratory that will test the blood sample for certain health conditions, including CF. In some states, newborn screening involves two blood samples, one at birth and one a few weeks later.

CF Newborn Screening Can Differ by State

All 50 states and the District of Columbia screen newborns for CF, but the method for screening may differ from state to state. 

Every state's CF newborn screening program begins with a blood test from the baby to check the levels of a chemical made by the pancreas called immunoreactive trypsinogen (IRT).

IRT is normally found in small levels in the body. In people who have CF, IRT levels tend to be high but IRT levels can also be high if a baby is premature, had a stressful delivery, or for other reasons. 

States use two different methods for newborn screening. 

  • Some states test IRT levels twice before conducting a DNA test. These states are called IRT-IRT-DNA states. 
  • Some states test IRT levels once before conducting a DNA test. These are called IRT-DNA states.

To learn more about the newborn screening method used in the state where your baby was born, please contact

Understanding Results From Newborn Screening

Results from newborn screening for CF can take longer than one week after a blood sample is collected. Ask your baby's primary health care provider when you can expect results.

When high IRT levels are detected in the blood, the results of the newborn screening are said to be positive. A positive newborn screening result tells you that your baby might have CF. 

Watch the "Cystic Fibrosis Newborn Screening" video from Nemours to learn why an abnormal test result does not necessarily mean your baby has CF.

What to Do When Newborn Screening Results Are Positive for CF

If your baby had a positive NBS or you received a positive prenatal genetic test, it’s important to schedule a sweat test once your newborn is 48 hours old. At the latest, babies with a positive NBS or prenatal genetic test should have a sweat test performed by the age of 4 weeks to ensure that any health issues or changes can be found early and treated quickly.

The sweat test will measure how much salt is in your baby's sweat. This test is the only way to diagnose CF, although other forms of testing can help confirm or inform the diagnosis if the sweat test results are inconclusive.

The sweat test should be done at a CF Foundation-accredited care center. The staff will work to schedule the sweat test as soon as possible.

For more information about scheduling a sweat test appointment, please contact the CF care center closest to you.

Hear from other parents who received positive Newborn Screening results in this short video from Nemours.
Share this article
Diagnosis | Intro to CF
An Introduction to Cystic Fibrosis for Patients and Their Families Download (PDF)
My Baby is a CF Carrier Download (PDF)

Hear the latest in newborn screening, delayed diagnosis, and how these impact health equity alongside others living with and studying CF at ResearchCon April 30 – May 1.

Register today
You Might Also Be Interested
Have questions? We’re here to help. Call us at 1-800-FIGHT CF

Mon - Thu, 9 am - 7 pm ET
Fri, 9 am - 3 pm ET


More Ways To Get Help