Patent Ductus Arteriosus

About

Enlarge

The ductus arteriosus is a passageway between two major blood vessels: the pulmonary artery and the aorta. The pulmonary artery carries oxygen-poor (blue) blood from the heart's right side to the lungs, where it picks up a fresh supply of oxygen. The aorta carries the oxygen-rich blood from the heart's left side to the rest of the body.

In an unborn baby, the blood flow bypasses the lungs because oxygen and nutrients are received from the mother. Once a newborn starts breathing, the ductus arteriosus must close in order to deliver fully oxygenated (red) blood to the body. In most cases, this happens within a few days following birth. If the ductus arteriosus remains open (referred to as "patent") blood that should have gone through the aorta and on to the body goes back into the lungs. This extra blood causes higher pressure in the blood vessels in the lungs. The ability of the lung vessels to adapt to the extra blood flow depends on the size of the PDA. The lungs can cope with this extra blood flow and pressure for a while, but without treatment, the blood vessels in the lungs may become damaged by the extra pressure. A PDA can also lead to heart failure.

It is not known why the ductus arteriosus remains open in some children. PDA is seen more often in premature infants and in infants born to a mother who had rubella during the first trimester of pregnancy. PDA occurs in 1 of 2,500-5,000 infants, and females are two to three times more likely than males to have a PDA.

Surgery was once required for closing a patent ductus, but today medications can often be used to close the ductus. Children who have had successful PDA closure should live long and healthy lives.