What is patent ductus arteriosus?

Diana Meeks
Diana Meeks on behalf of Sigma Nursing
Family Practitioner

Patent ductus arteriosus is a birth defect of the heart caused by the large artery not closing properly. Before birth, this artery allows blood to bypass the lungs, since oxygen is not needed in the blood while the fetus is in the womb. Normally, this artery closes by itself shortly after birth so that blood will then go to the lungs to get oxygen. If it does not close, heart failure can occur. Medicine or surgery is usually used to treat this heart birth defect.

Dr. Jeanne Morrison, PhD
Family Practitioner

Patent ductus arteriosus (PDA) is a fairly common heart defect. A PDA results in abnormal blood flow between the aorta and the pulmonary artery.

Before birth, these arteries are connected by a structure called the ductus arteriosus. This structure is an essential part of fetal blood circulation. After birth, as the oxygen concentration in the blood increases, the ductus arteriosus closes.

If the ductus arteriosus does not close, the opening allows oxygen-rich blood from the aorta to mix with oxygen-poor blood from the pulmonary artery. This causes strain on the heart and increased pressure in the pulmonary arteries.

A heart murmur is often the first sign of a PDA.  Other signs and symptoms can include change in respiratory pattern, poor feeding and growth, tiring easily and sweating with exertion.

Before birth, the blood vessel called the ductus arteriosus connects the two major arteries from the heart. One is the pulmonary artery, which carries blood from the heart to the lungs, and the second is the aorta, which carries blood from the heart to the body. As the baby develops, the ductus arteriosus diverts blood away from the lungs, which are collapsed when the baby is inside the mother’s womb. The ductus arteriosus carries the blood to the aorta to be distributed to the body. When the baby is born and begins to breathe, the ductus arteriosus is supposed to close within a few days. But in some babies, it stays open and this is called a persistent patent ductus arteriosus (PDA). This allows blood to flow directly from the aorta into the pulmonary artery. As a result, there is too much blood flowing toward the lungs, placing strain on the heart and increasing the blood pressure in the lung arteries.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.