What is cystic fibrosis?
Cystic fibrosis is a life-long illness that is usually diagnosed in the first few years of life. The disorder causes problems with digestion and breathing.

What are the health needs of children with cystic fibrosis?
The digestive problems can usually be treated by taking medicine daily. To treat lung problems, most children with CF need to have respiratory therapy for about a half hour every day; this helps clear mucus from the lungs.

Do all people with cystic fibrosis have the same symptoms?
No. Some individuals have milder or more severe symptoms than others for reasons that are not completely understood.

What is the purpose of cystic fibrosis carrier testing?
The purpose of CF carrier testing is to see if a couple is at increased risk for giving birth to a child who will have CF. Cystic fibrosis carrier testing is a laboratory test done on a sample of blood or saliva.

What causes cystic fibrosis?
Cystic fibrosis is a genetic disorder. Some genes do not function properly because there is a mistake in them. If a gene has a mistake, it is said to be altered or changed. For some diseases — like CF — both genes of the pair have to be altered for a person to have the disease.

Could I be a carrier of cystic fibrosis?
Yes. You could be a carrier of CF even if no one in your family has CF and even if you already have children without CF.

If my test result is normal, could I still be a carrier?
Yes. There are some mutations in the CF gene that the current test cannot find.

However, these unknown CF mutations are rare.

If the test shows I am a carrier, what should I do?
If the test shows that you are a carrier, the next step is to test the baby's father. Both parents must be carriers for the baby to have CF.

What if both my partner and I are cystic fibrosis carriers?
If two people who are both carriers have a child, that child may have CF. When two carriers have a child together, there is a 1-in-4 (25 percent) chance with each pregnancy that the child will have CF.

If I had cystic fibrosis testing, do I need it again?
If the test shows you are a carrier, the result is definite and will not change. However, if you are a carrier and have a new partner for a future pregnancy, testing should be considered for that new partner.

How do I decide whether or not to have carrier testing?
After learning about CF carrier testing, some people decide to have testing, and others decide against it.

Possible reasons to be tested:

• If CF seems like a very serious disorder to you
• If the chance of being a CF carrier seems high to you; this may be especially likely if a member of your family or your partner's family has CF or is a known carrier
• If you and the baby's father would consider amniocentesis or CVS
• Because test results are usually reassuring

Possible reasons not to be tested:

• If CF does not seem like a very serious disorder to you
• If the chance of being a CF carrier seems low to you; this may be especially likely if you are Asian American or African American
• If you and the baby's father would never consider having amniocentesis or CVS
• Because the test is not perfect and will not identify all carriers

This excerpt from ACOG's Patient Education Pamphlet is provided for your information. It is not medical advice and should not be relied upon as a substitute for visiting your doctor. If you need medical care, have any questions, or wish to receive the full text of this Patient Education Pamphlet, please contact your obstetrician-gynecologist.