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 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.

Overview

A PDA is a type of congenital 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. Some children need treatment to close their PDAs.

If your baby is born with another heart defect (in addition to PDA) that decreases blood flow from the heart to the lungs or that decreases the flow of oxygen-rich blood to the body, medicine may be given to keep the ductus arteriosus open.

This helps maintain blood flow and oxygen levels until doctors can do corrective surgery for the heart defect.

Outlook

PDA is a relatively common congenital heart defect in the United States. The condition occurs more often in premature infants (on average, occurring in about 8 of every 1,000 births). However, PDA also occurs in full-term infants (on average, occurring in about 2 of every 1,000 births).

Premature babies who have PDA are more vulnerable to its effects. PDA is twice as common in girls as it is in boys.

The next section provides more information about a normal heart compared to a heart with PDA. See that section for a more detailed description of the anatomy and circulation of a normal heart.

Revised June 2009