Overview

Pulmonary atresia (uh-TREE-zhuh) is a heart condition present at birth. That means it is a congenital heart defect. In this condition, the valve that helps move blood from the heart to the lungs doesn't form correctly. The valve is called the pulmonary valve.

Instead of a valve that opens and closes, a solid sheet of tissue forms. So, blood can't travel its usual path to get oxygen from the lungs. Instead, some blood travels to the lungs through other natural passages within the heart and its arteries.

A baby in the womb needs these other passages. But they usually close soon after birth.

Pulmonary atresia is a life-threatening condition that needs emergency treatment. Treatment includes surgery to repair the heart and medicines to help the heart work better.

Types

Symptoms

When to see a doctor

Most often, healthcare professionals find pulmonary atresia soon after birth. If your baby has symptoms of this condition after you've left the hospital, get medical help right away.

Causes

The cause of pulmonary atresia is not clear. During the first six weeks of pregnancy, the baby's heart begins to form and starts beating. The major blood vessels that run to and from the heart also begin to form during this crucial time. It's at this point in a baby's development that a congenital heart defect such as pulmonary atresia may start to arise.

To understand how pulmonary atresia happens, it may be helpful to know how the heart works.

Risk factors

Pulmonary atresia happens as the baby's heart forms during pregnancy. Some health conditions or drug use during pregnancy may raise a baby's risk of pulmonary atresia or other congenital heart defects. Risk factors include:

  • Obesity.
  • Alcohol or tobacco use.
  • Diabetes.
  • Use of some types of medicines during pregnancy, such as some acne and blood pressure medicines.

Some types of congenital heart defects run in families. This means they are inherited. If you or someone in your family was born with a heart condition, including pulmonary atresia, ask your healthcare team if genetic screening is right for you. Screening can help show the risk of some congenital heart defects in future children.

Complications

Without treatment, pulmonary atresia most often leads to death. After surgery for pulmonary atresia, babies need regular health checkups throughout their lives to watch for complications.

Complications of pulmonary atresia may include:

  • Infection of the inner lining of the heart and valves due to germs. This is called infectious endocarditis.
  • Irregular heartbeats, called arrhythmias.
  • Weakening of heart function.

Prevention

It might not be possible to prevent pulmonary atresia. But getting good prenatal care is important. Some things you can do before or during pregnancy might help lower your baby's risk of congenital heart defects. They include:

  • Manage other health conditions. If you have diabetes, keep your blood sugar in check. For other conditions that need medicines, talk with your healthcare professional about taking these medicines while pregnant.
  • Don't smoke and don't be around others who smoke. If you smoke, quit. Smoking during pregnancy raises the risk of a congenital heart defect in the baby.
  • Aim for a healthy weight. Obesity raises the risk of having a baby with a congenital heart defect.
  • Get recommended vaccinations. Having rubella, also called German measles, during pregnancy can cause trouble with the way a baby's heart develops. A blood test done before pregnancy can check if you're immune to rubella. A vaccine is available for those who aren't immune.

June 12, 2026

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  1. Altman CA. Evaluation of suspected critical congenital heart disease (CHD) in the newborn. https://www.uptodate.com/contents/search. Accessed Oct. 12, 2025.
  2. Park MK, et al., eds. Cyanotic congenital heart defects. In: Park's The Pediatric Cardiology Handbook. 5th ed. Elsevier; 2022. https://www.clinicalkey.com. Accessed Oct. 5, 2025.
  3. Axelrod DM, et al. Pulmonary atresia with intact ventricular septum (PA/IVS). https://www.uptodate.com/contents/search. Accessed Oct. 5, 2025.
  4. Harris K. AllScripts EPSi. Mayo Clinic. Sept. 5, 2025.
  5. Zitelli BJ, et al., eds. Cardiology. In: Zitelli and Davis' Atlas of Pediatric Physical Diagnosis. 8th ed. Elsevier; 2023. https://www.clinicalkey.com. Accessed Oct. 5, 2025.
  6. Phan A, et al. Congenital pulmonary vascular anomalies and disease. Radiologic Clinics of North America. 2025; doi:10.1016/j.rcl.2024.06.002.
  7. Jaggers J, et al. 2025 American Association for Thoracic Surgery Congenital Cardiac Surgery Working Group: Expert consensus document on the management of patients with pulmonary atresia with intact ventricular septum. Journal of Thoracic and Cardiovascular Surgery. 2025; doi:10.1016/j.jtcvs.2025.03.034.
  8. Single ventricle defects. American Heart Association. https://www.heart.org/en/health-topics/congenital-heart-defects/about-congenital-heart-defects/single-ventricle-defects. Accessed Sept. 12, 2025.
  9. How the healthy heart works. American Heart Association. https://www.heart.org/en/health-topics/congenital-heart-defects/about-congenital-heart-defects/how-the-healthy-heart-works. Accessed Oct. 12, 2025.
  10. Medical review (expert opinion). Mayo Clinic. July 21, 2023.
  11. Fetal circulation. American Heart Association. https://www.heart.org/en/health-topics/congenital-heart-defects/symptoms--diagnosis-of-congenital-heart-defects/fetal-circulation. Accessed Oct. 12, 2025.
  12. Kawai S, et al. Journal of the American Heart Association. Association between maternal factors in early pregnancy and congenital heart defects in offspring: The Japan environment and children's study. 2023; doi:10.1161/JAHA.122.029268.
  13. Chu VH. Prevention of endocarditis: Antibiotic prophylaxis and other measures. https://www.uptodate.com/contents/search. Accessed Oct. 13, 2025.