Newborn Screening for CF

Newborn screening (NBS) is a nationwide program to identify babies born with certain health conditions, including cystic fibrosis. While a sweat test should be used 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.

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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 tells you that your baby might have CF and that further testing through a sweat test is required. 

The Importance of Early Diagnosis of CF

Newborn screening (NBS) for cystic fibrosis is done in the first few days after birth. By diagnosing CF early, CF health care providers can help parents learn ways to keep their child as healthy as possible and 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. Early diagnosis and treatment can: 

  • Improve growth.
  • Help keep lungs healthy.
  • Reduce hospital stays.
  • 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 other reasons. 

Some states only test IRT levels on the first blood test. These are called IRT-only states. Other states conduct both an IRT and a DNA test. These are called IRT-DNA states. Learn more about these screening methods.

If you have questions about newborn screening or genetic testing for CF, please contact a CF Foundation-accredited care center or talk with your doctor. 

Based on your baby's newborn screening results, you may be asked to bring your baby to a CF Foundation-accredited care center for sweat testing to either rule out or confirm a CF diagnosis.

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. 

The CF screening test checks for IRT, which is normally found in small amounts in the body. 

When the pancreas is stressed before a baby is born, more IRT is released into the baby's blood. The IRT level can be high for several reasons, including a premature or stressful delivery, or for other reasons. IRT levels also tend to be high in people who have CF. When high IRT levels are detected in the blood, the results of the newborn screening are said to be positive.

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

A positive newborn screening result tells you that your baby might have CF and that further testing through a sweat test is required in order to rule out or diagnose CF. 

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.

If your baby had a positive NBS or you received a positive prenatal genetic test, it’s important to schedule a sweat test as soon as possible once your newborn reaches 10 days of age. 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. 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.

When the Sweat Test Confirms a CF Diagnosis 

First of all, remember that you are not alone. There is a strong and growing network of people with CF, other parents and families, health professionals and care centers to help you and your baby. Thanks to this network -- and to aggressive research and new therapies -- people with CF are living longer and healthier lives.

To learn more about how other families have coped with a positive CF diagnosis, watch our "CF Newborn Screening and Diagnosis" video.

As soon as possible, you should contact a CF Foundation-accredited care center. The health care professionals at these centers will help you learn more about CF and become your partners in creating a plan to keep your baby healthy.

What Can I Do To Keep My Baby Healthy? 

The most important thing is to work closely with the CF health care professionals at your care center. They will work with you to develop a plan for your baby's health -- including avoiding germs, eating smart, and keeping lungs clear of mucus.

Your baby will need to follow a daily treatment routine to stay healthy and maintain optimal lung function.

Hear other parents of children with CF share personal experiences about how they cared for their baby during the first year.

Thanks to the community of people living with CF and their families who participate in CF Foundation-supported research and work with care teams at CF Foundation-accredited care centers across the country, there are more options available to treat CF than ever before. These include drugs to help clear CF mucus out of the airways, reduce inflammation, fight germs, and help your child grow.

There are also new medications called cystic fibrosis transmembrane conductance regulator (CFTR) modulators designed to treat the underlying cause of CF in people with certain CF gene mutations, and similar therapies are in development for more people living with CF.

A diagnosis of CF can lead to many different emotions. Understanding how to cope with these emotions is the first step in learning how to raise a happy, healthy child.  

My Baby Is a CF Carrier

If your baby's newborn screening results found one CF gene mutation and the sweat test was negative (normal), your baby does not have CF. A test result of one mutation means that your baby is a CF carrier. A CF carrier is healthy and does not have the disease. 

We encourage you to talk with your child when he or she is old enough to understand genetics. It will be important for your child to know that he or she could pass the CF gene mutation to his or her future children. His or her partner might want to get CF carrier testing if they plan to have children. 

CF gene mutations are shared in families. Because of this, you should tell your blood relatives that they could be carriers of a CF gene mutation, so that they and their partners can decide if they would like to be tested. 

You and your child can discuss being a CF carrier with your child's doctor, a genetic counselor, or a genetics nurse specialist when your family is ready for that conversation.

Researchers are making rapid progress in understanding CF genetics. Much more will be known about CF genetics when your child is ready to have children.

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