Understanding the Results
My baby’s newborn screening test for CF was positive (abnormal). Does this mean my baby has CF?
Not necessarily. The newborn screen shows that your baby might have a health condition called cystic fibrosis (CF). Most babies who have a positive (abnormal) screen result for CF do not have CF. You need to have a diagnostic test, called a sweat test to know for sure.
back to top
What are the chances my baby has CF?
The diagnostic test, or sweat test, is the most accurate way to know if your baby has CF. However, in some states, the newborn screening (NBS) test is done in such a way that it can tell you how likely it is that your baby has CF. If your baby was screened in a state that measures DNA in addition to measuring the IRT level, the screening results will tell you more about the chances that your baby has CF.
To learn what kind of testing your baby had, see How can I tell which screening method my state uses?
In states that measure DNA as well as IRT:
- Babies with two CF gene mutations found through newborn screening are very likely to have CF.
- Babies with only one gene mutation found on a newborn screening may have CF. They are much more likely to be healthy carriers of CF than to have the disease cystic fibrosis. In most states, fewer than three out of 100 babies who have a positive newborn screen with one gene mutation will actually have CF. These babies with only one gene mutation are carriers of CF.
- Babies who only carry one CF gene mutation will sometimes have a high IRT level. However, it is also possible that the baby might still have a second gene mutation which was not looked for in the newborn screening test — and might still have CF. The chance of a baby with one mutation having CF depends on how many mutations were screened and the child's ethnic background. It is most likely that a baby with one mutation is a healthy carrier of CF. However, more testing, such as a sweat test, needs to be done.
- Babies with very high IRT levels but no CF gene mutations are unlikely to have CF. As a precaution, the health care provider might ask parents to bring the baby to a CF Foundation-accredited care center for a sweat test.
back to top
My baby’s screening test was positive (abnormal). What happens next?
Most babies who need to have a sweat test because of an abnormal newborn screen do not have CF. It is important to be sure that they do not.
If your baby’s screening test was “abnormal” or “positive” for CF, this means that your baby might have CF. A second type of test, the sweat test, is needed to find out if your baby has CF.
The sweat test will measure how much salt is in your baby’s sweat. This test is the best way to diagnose CF. How long you have to wait before getting a sweat test can vary by clinic, your baby’s needs and situation.
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.
For more information, visit the Sweat Test section.
back to top
I had a negative CF blood test when I was pregnant. Does my baby still need to be tested for CF?
Yes. Any baby who had a positive (abnormal) CF newborn screening result should get a sweat test to find out if the baby has CF.
back to top
Why is it important to screen for CF at birth?
It is important to diagnose CF early. Research shows that children who receive CF care early in life have better nutrition and are healthier than those who are diagnoses later. Good nutrition in CF is important for overall health and well-being.
back to top
How do others handle the feelings that come with a positive (abnormal) NBS?
Getting the news of a positive CF newborn screen can be stressful. Lisa Greene, a mom of two children with CF, explains:
Our baby is born. We are excited and joyful. Then we find out that there is a chance our child might have cystic fibrosis. Some of us feel disbelief. Others feel worry, fear, sadness or even anger. Some of us seek more information; others choose not to.
All of these feelings and responses are normal. Everyone handles difficult news differently. Our reaction depends on our personality traits, background, and culture. The waiting for answers and information can be the hardest part. Knowing that you are not alone can be comforting.
The most important thing right now is for you to love, enjoy and care for your new baby. Continue to build and strengthen your bond with your baby with lots of holding, rocking, talking, singing, eye contact, smiles, touch, play and meeting your baby’s needs for food and cleanliness.
Caring for your baby can be exhausting so you might need some help. It’s important that you take good care of yourself, too.
Research shows that the parents' emotional state is very important. If you are feeling depressed, anxious and are having problmes doing your normal daily activiites, talk with your doctor. (Your family’s health care provider can help direct you to resources.)
Even if your child does have CF, you will get through this. The world of CF is filled with caring professionals, loving organizations, and supportive parents. They will provide you with resources, information, support, and the latest medical research that continues to enhance and lengthen our children’s lives.
And you will find that as you teach your child the importance of daily healthy decisions, you are likely to raise a motivated child who sets an example of maturity, responsibility, and inspiration for all who come in contact with him or her.
back to top