Pulmonary atresia (PA) is a heart defect. It happens when the fetal heart doesn’t form as it should. This can happen during the first 8 weeks of pregnancy.

PA is a problem with the opening of the pulmonary valve. This valve connects the right ventricle and the main pulmonary artery, which carries blood to the lungs. With pulmonary atresia, blood can’t flow to the lungs.

For more information regarding pediatric PA services in St. Louis or to make an appointment, please call 314.454.5437 or 800.678.5437 or email us.

Since blood can’t flow from the right ventricle to the pulmonary artery, it takes other routes. The normal opening (foramen ovale) between the right and left upper chambers (atria) of the fetal heart normally closes soon after birth. In a newborn with PA, it stays open to let oxygen-poor (blue) blood flow from the right atrium to the left atrium to mix with the oxygen-rich (red) blood returning from the lungs. This mixture of oxygen-poor and oxygen-rich blood is then pumped by the left ventricle out to the body.

In addition, a newborn with PA must rely on a temporary connection (called ductus arteriosus) between the aorta and the pulmonary artery. The ductus arteriosus is also part of normal fetal blood flow. But it also closes soon after birth. While it is open, some of the mixed blood pumped by the left ventricle flows to the lungs via the patent ductus (PDA) and picks up oxygen. When PA is present, and the ductus arteriosus closes, no blood reaches the lungs to get oxygen. 

Because the blood doesn't get enough oxygen, every cell in the newborn's body gets less oxygen. A newborn with pulmonary atresia can’t live long without treatment.

In some cases, the tricuspid valve or right ventricle may be underdeveloped with significant enlargement of the muscle.


Some congenital heart defects may happen more often in certain families (genetic). Most of the time, there is no known cause.


Symptoms may happen shortly after birth or later as the ductus arteriosus closes. The most obvious symptom is a bluish color of the skin (cyanosis) in a newborn.

These are other common symptoms:

  • Fast or troubled breathing
  • Poor feeding
  • Weakness and sleepiness
  • Pale, cool, or clammy skin
  • Seizures

The symptoms of PA may look like other health conditions or heart problems. Make sure your child sees his or her healthcare provider for a diagnosis.


PA may be found during a routine ultrasound during pregnancy.

At birth, the healthcare providers and nurses will examine your baby. They will listen to your baby's heart and lungs with a stethoscope and note any signs of a heart defect.

Testing for heart defects varies by the child's age, condition, and other things. Some tests that may be done include:

  • Pulse oximetry. This is a test to check oxygen levels in the blood through a tiny clip or band on the baby's finger or toe. PA causes low oxygen levels.
  • Chest X-ray. A chest X-ray shows pictures of the heart and lungs. It may show structural problems that occur with PA.
  • Electrocardiogram (ECG). This test records the electrical activity of the heart. It shows abnormal rhythms and heart muscle stress.
  • Echocardiogram (echo). Echo uses sound waves to record a moving picture of the heart and heart valves. This test is the best one to diagnose PA.
  • Cardiac catheterization (heart cath). The baby gets medicine to sedate him or her. Then a thin, flexible tube (catheter) is put into a blood vessel in the groin and guided to the heart. A heart cath gives very detailed information about the heart. This includes blood pressure and oxygen measurements in the chambers of the heart, as well as the pulmonary artery and aorta. Contrast dye is also injected to better see the structures in the heart. 


Your baby will be treated by a pediatric cardiologist. This is a doctor with special training to treat heart problems in children.

Your baby will most likely be in the intensive care unit (ICU). At first, your baby may be put on oxygen, and possibly on a ventilator, to help with breathing. Your child may get IV medicines to help his or her heart and lungs work better.

The following treatments allow time for the oxygen levels in your baby's heart to even out while other repairs are planned:

  • An IV medicine called prostaglandin E1 is often given to keep the ductus arteriosus from closing. This lets blood get to the lungs for oxygen.
  • A cardiac cath may be done to diagnose the defect. In some cases, the pulmonary valve may be able to be opened with catheterization to avoid the need for open heart surgery. This is only an option if the tricuspid valve and the right ventricle are normal size.

Surgical repair

Your child will need surgery to improve blood flow to the lungs. What type of surgery your child has will depend on whether the tricuspid valve or right ventricle can deliver enough blood to the lungs. Usually, the surgeon will do a series of operations to reroute the blood flow to allow oxygen-poor blood to reach the lungs and pick up oxygen. The first surgery may be done shortly after birth. The final surgery is done when the child is a few years old.


Without surgery, the heart can’t pump oxygenated blood to the body and can’t support life. Surgery can be very successful in those with normal sized tricuspid valves and right ventricles.

As your child grows, he or she may need to limit physical activity. Your child may also have developmental delays. He or she may need therapy and special help.

For more information regarding pediatric PA services in St. Louis or to make an appointment, please call 314.454.5437 or 800.678.5437 or email us.

Living with

After the surgical repair and time for recovery in the hospital, your baby will be able to go home. Your doctor may recommend pain medicines such as acetaminophen or ibuprofen to keep your baby comfortable. Your child's heart care team will talk about pain control before your child goes home.

The nursing staff will show you how to give any special treatments at home, if needed. Or you may need a home health agency to help. Your child will likely need special formula and supplemental feedings to get enough nutrition.

You may get other instructions from your child's pediatric cardiologist and the hospital staff.

The outlook varies from child to child. Be sure to get regular follow-up care at a center offering pediatric congenital heart care. Your child likely will need more surgery.

After each surgery, your pediatric cardiologist will follow your baby’s recovery. He or she will make changes to medicines, help you with feeding problems, measure oxygen levels, and determine when and if it is time for the next surgery.

Your child may need to be on long-term antibiotics, or take antibiotics before dental or other procedures. Your healthcare provider can tell you if this is needed.

It is important that your child get all recommended vaccines. Talk with your healthcare provider about this.

Throughout your baby's life, pregnancy and non-heart surgeries may be very risky. They require careful evaluation and discussion with a cardiologist.

Your child will need regular follow-up care at a center offering pediatric or adult congenital heart care for the rest of his or her life.

When to Call a Healthcare Provider

Call your child's healthcare provider if your child has breathing or feeding problems, or has new symptoms.

Key Points

  • Pulmonary atresia is an abnormal development of the pulmonary valve.
  • Without repair, the heart can’t pump oxygenated blood to the body and can’t support life.
  • Your child will get special care in the hospital until surgery can be done.
  • Your child will continue to need special care after the surgery and once he or she is home. This includes special formula and supplemental feedings.
  • Your child will need lifetime follow-up care with a pediatric cardiologist and adult cardiologist familiar with congenital heart defects.
  • Your child will likely need more surgery.

Next Steps

Tips to help you get the most from a visit to your child’s healthcare provider:

  • Know the reason for the visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
  • Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
  • Ask if your child’s condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if your child does not take the medicine or have the test or procedure.
  • If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.

For more information regarding pediatric PA services in St. Louis or to make an appointment, please call 314.454.5437 or 800.678.5437 or email us.