Cystic fibrosis and your baby


  • Cystic fibrosis (also called CF) is a condition that causes thick mucus to build up in the body. This causes problems with breathing and digestion.

  • CF is passed from parents to children through genes. A baby has to inherit a CF gene from both parents to have CF.

  • All babies have a newborn screening test for CF so it can be found and treated early.

  • Treatment can include medicines and chest therapy to help with your baby’s breathing and digestion.

  • If you’re breastfeeding, you may need to supplement breast milk with vitamins and calories to help your baby grow and gain weight. 

What is cystic fibrosis?

Cystic fibrosis (also called CF) is a chronic health condition in which very thick mucus builds up in the body. This causes problems with breathing and digestion. Digestion is the way your body processes the food you eat. A chronic health condition is one that lasts for 1 year or more that needs ongoing medical care and that can limit your usual activities and affect daily life.

Mucus is a fluid that normally coats and protects parts of the body. It’s usually slippery and watery. But in CF, the mucus is thicker and sticky. It builds up in the lungs and digestive system and can cause problems with how you breathe and digest food. The buildup of mucus in the body makes it easy for harmful bacteria to grow. This can lead to infections.

Health problems caused by CF can get worse over time and become life-threatening. But with regular care and treatment from health care providers, people with CF are living healthier lives. 

More than 30,000 people in the United States have CF. About 1 in 4,000 babies is born with CF. Most children with CF are diagnosed by age 2. 

What causes CF?

CF is inherited (also called genetic). This means it’s passed from parents to children through genes. A gene is a part of your body’s cells that stores instructions for the way your body grows and works. Genes come in pairs — you get one of each pair from each parent. CF is one of the most common genetic conditions in the United States.

Sometimes the instructions in genes change. This is called a gene change (also called a mutation). The gene change in CF affects a protein that controls the balance of salt and water in the body. This causes the body to make thick, sticky mucus and salty sweat.

Parents can pass gene changes to their children. Sometimes a gene change can cause a gene to not work correctly. Sometimes it can cause birth defects or other health conditions. Birth defects are health conditions that are present at birth. They change the shape or function of one or more parts of the body. Birth defects can cause problems in overall health, how the body develops or how the body works.

A baby has to inherit a gene change for CF from both parents to have CF. If your baby inherits the gene change from just one parent, she has the gene change for CF, but she doesn’t have the condition. When this happens, your baby is a CF carrier. A CF carrier has the gene change but not the condition. About 1 in every 20 people is a CF carrier.

If you and your partner both have CF, your baby will have CF. But most men with CF are infertile and can’t get their partner pregnant. If you and your partner are both CF carriers, there is a:

  • 3-in-4 chance (75 percent) that your baby won’t have CF
  • 1-in-2 chance (50 percent) that your child won’t have CF but will be a CF carrier
  • 1-in-4 chance (25 percent) that your child will have CF
  • 1-in-4 chance (25 percent) that your child will not have CF and not be a carrier 

Genetic counseling can help you understand your chances of passing CF to your baby. A genetic counselor is a person who is trained to help you understand about how genes, birth defects and other medical conditions run in families, and how they can affect your health and your baby's health. Ask your health care provider if you need help finding a genetic counselor. Or contact the National Society of Genetic Counselors.

How do you know if your baby has CF? 

All babies get tested for CF as part of newborn screening before they leave the hospital after birth. Newborn screening checks for serious but rare and mostly treatable conditions at birth. It includes blood, hearing and heart screening. With newborn screening, CF can be found and treated early.

To do the screening, your baby’s health care provider takes a few drops of blood from your baby’s heel to test it for CF and other conditions. The blood is dried on a special paper and sent to a lab for testing. The lab then sends the results back to your baby’s provider.

If your baby’s newborn screening results aren’t normal, your baby needs a diagnostic test to check for CF. A diagnostic test is a medical test to see if your baby does or doesn’t have a certain health condition. It’s different from a screening test that tells if your baby is more likely than others to have a condition. The diagnostic test helps your baby’s provider know for sure if your baby has CF or if there’s some other cause for the screening test results. 

Your provider may recommend these diagnostic test to see if your baby has CF:

  • A sweat test. This is a simple, painless test that checks the amount of salt in your baby’s sweat. Babies with CF have much more salt in their sweat than babies without. Your baby may get two or more sweat tests.
  • A blood test to check your baby’s genes for CF 

If your baby has CF, she starts treatment right away, within 1 to 3 days of the diagnosis. Treatment is best at an accredited CF care center that has all the health care providers who specialize in treating babies with CF. Signs and symptoms of CF include: 

  • Coughing, wheezing or shortness of breath or having a lot of mucus in the lungs or lung infections, like pneumonia and bronchitis
  • Salty skin
  • Stuffy nose, sinus infections or nasal polyps (small growths of tissue inside the nose)
  • Slow weight gain and growth
  • Meconium ileus. This is when meconium gets stuck in a newborn’s intestine. Meconium is a baby’s first bowel movement. It can be green, brown or black in color.
  • Bowel movements that smell bad, happen often and are loose, large or look greasy. A bowel movement is solid waste that leaves the body through the rectum.
  • Constipation, stomach pain or bloating

What problems can CF cause for babies and young children?

Some cases of CF are more severe than others. Babies with CF are often sick with infections and need a lot of medical care. CF can cause these problems for babies:

  • Lung and breathing problems. When the mucus builds up in the lungs, it blocks airways (tubes that carry air in and out of the lungs) and causes breathing problems and infections. As a baby with CF gets older, lung problems can get worse. This can lead to serious and sometimes deadly lung damage.
  • Problems with digestion. When mucus builds up in the digestive system, it blocks tubes in the pancreas. The pancreas is an organ in the belly that makes enzymes that help the body break down food. Blockages in the pancreas can make it hard for the enzymes to get to the small intestine. When this happens, your baby may not get the nutrients she needs from food to grow and stay healthy. Some children with CF gain weight and grow normally. But many grow more slowly than children without CF.

What kind of providers does your baby need to treat CF?

Your baby needs a team of providers who specialize in treating CF in infants and children. The providers often work at an accredited CF care center. You may get your CF care at an accredited CF care center. These centers have expert providers who specialize in treating people with CF.

Your baby’s care team can include you and your baby as well as:

  • A pediatrician. This is a doctor who has training and education to take care of babies and children.
  • A nurse who helps you manage your baby’s overall care
  • A CF dietitian who helps you with your baby’s nutrition
  • A CF social worker or psychologist who helps you manage CF as part of your baby’s daily life
  • A CF respiratory therapist who helps your child with breathing and keeping your baby’s airways clear
  • A CF physical therapist to help with your baby’s physical development 

If your baby has CF, how are lung and breathing problems treated? 

Many lung infections in babies with CF are caused by bacteria that may be hard to treat with medicines like antibiotics. These infections can lead to lung damage. Your child’s treatment depends on the how severe his condition is.

To help your baby’s breathing, keep your baby away from smoke from tobacco products, like cigarettes and cigars. Ask others, especially all caregivers, to not smoke and to keep your baby away from smoke.

Certain medicines can help babies and children with CF breathe better and prevent infections. These include: 

  • Antibiotics. These are medicines that kill infections caused by bacteria. They’re sometimes used to help prevent infections. They’re usually given by mouth. If an infection is severe, your baby may get antibiotics through an IV (also called intravenous). This is when medicine is given through a needle into a vein.
  • Anti-inflammatory medicines. These medicines can help reduce lung swelling that makes breathing hard.
  • Bronchodilators. These inhaled medicines help open the airways by relaxing the muscles around them.
  • Hypertonic saline. Inhaling this salt-water mist can help thin the mucus.  
  • Medicines that help thin mucus to help improve air flow and prevent the build-up of harmful bacteria
  • The flu vaccine for babies older than 6 months. The flu vaccine helps protect your baby from the flu.

Other treatments to help your baby’s breathing include:

  • Chest therapy to help loosen mucus and clear the airways to the lungs. This can include clapping on your child’s back with a cupped (rounded) hand or a small cup called a chest percussor to help your baby cough mucus up and out of the lungs. Your baby’s providers can teach you how to do this therapy with your baby. A vibrating vest also may be used to help a child cough up mucus.
  • A plan to help make sure your baby gets plenty of physical activity
  • Chest X-rays to check your baby’s lungs
  • Lung transplant. This treatment is used only if your child’s CF becomes life-threatening.

If your baby has CF, how are growth and digestion problems treated?

Treatment for CF focus on getting nutrients from food that help your baby grow and gain weight. Treatment may include: 

  • Medicine called pancreatic enzyme supplements that help the body digest food and get nutrients from food
  • Vitamin supplements, especially vitamins A, D, E and K
  • A salt supplement to help your baby get the right amount of salt
  • Calorie supplements added to breast milk or formula. You also can add calories to solid foods when your baby starts eating them. Don’t give your baby juice, water or other liquid in the first year of life. These fluids have less calories and nutrients than breast milk or formula.  
  • Tube feedings. If your baby has a lot of trouble gaining weight, she may be fed formula through a tube into her stomach.  

Is breast milk safe for a baby with CF?

Yes. Breast milk is the best food for babies in the first year of life. And even if you have CF, breast milk is good for your baby.

Moms can pass medicine to their babies in breast milk. And some medicines may be harmful to a baby. If you’re getting treatment for CF, talk to your provider to make sure the medicines you take are safe for your baby. You may need to see about changing to a safer medicine. Make sure your prenatal provider, your CF provider and your baby’s provider know about any medicine you take. Don’t start or stop taking any medicine without talking to your providers first.

More information

Cystic Fibrosis Foundation

See also: Cystic fibrosis and pregnancy

Last updated: May, 2019