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What Is Patent Ductus Arteriosus?

Patent ductus arteriosus (PDA) is a heart problem that occurs soon after birth in some babies. In PDA, abnormal blood flow occurs between two of the major arteries connected to the heart.

Before birth, the two major arteries—the aorta and the pulmonary (PULL-mun-ary) artery—are connected by a blood vessel called the ductus arteriosus. This vessel is an essential part of fetal blood circulation.

Within minutes or up to a few days after birth, the vessel is supposed to close as part of the normal changes occurring in the baby's circulation.

In some babies, however, the ductus arteriosus remains open (patent). This opening allows oxygen-rich blood from the aorta to mix with oxygen-poor blood from the pulmonary artery. This can put strain on the heart and increase blood pressure in the lung arteries.

Normal Heart and Heart With Patent Ductus Arteriosus

Figure A shows the organs that primary ciliary dyskinesia can affect. Figure B shows a cross-section of the trachea (windpipe). Figure C shows a closeup view of normal cilia lining the trachea. The cilia move together in wave-like motions to transport mucus toward the mouth. Figure D shows a closeup view of faulty cilia lining the trachea. The cilia are deformed and do not move together, causing a buildup of mucus.

Figure A shows the interior of a normal heart and normal blood flow. Figure B shows a heart with patent ductus arteriosus. The defect connects the aorta with the pulmonary artery. This allows oxygen-rich blood from the aorta to mix with oxygen-poor blood in the pulmonary artery.

Go to the "How the Heart Works" section of this article for more details about how a normal heart works compared with a heart that has PDA.


PDA is a type of congenital (kon-JEN-ih-tal) heart defect. A congenital heart defect is any type of heart problem that's present at birth.

If your baby has a PDA but an otherwise normal heart, the PDA may shrink and go away. However, some children need treatment to close their PDAs.

Some children who have PDAs are given medicine to keep the ductus arteriosus open. For example, this may be done if a child is born with another heart defect that decreases blood flow to the lungs or the rest of the body.

Keeping the PDA open helps maintain blood flow and oxygen levels until doctors can do surgery to correct the other heart defect.


PDA is a fairly common congenital heart defect in the United States. Although the condition can affect full-term infants, it's more common in premature infants.

On average, PDA occurs in about 8 out of every 1,000 premature babies, compared with 2 out of every 1,000 full-term babies. Premature babies also are more vulnerable to the effects of PDA.

PDA is twice as common in girls as it is in boys.

Doctors treat the condition with medicines, catheter-based procedures, and surgery. Most children who have PDAs live healthy, normal lives after treatment.


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September 26, 2011