Ductus Arteriosus

The Ductus Arteriosus (DA) is a temporary blood vessel connecting the main vessel leading to the lungs to the main vessel of the body. If the vessel stays open after birth it is called a Patent Ductus Arteriosus; patent meaning open. What the DA does is before birth the fetus receives oxygen from the placenta. The fetus does not use his/her lungs, so very little blood needs to go to them. So what is does is bypass the lungs and go to the rest of the body. After birth the baby’s lungs take over and his/her body stops producing the chemicals that are needed to keep the DA open. The DA usually closes a few hours to a day after the baby is born.

When the DA stays open; blood goes in the opposite direction; from the body to the lungs causing a build up of blood in the baby’s lungs. This build up makes it harder for the baby to breath, increasing the amount of work on the heart, which can result in heart failure. Medication will first be used to treat the problem. Idomethacin is a drug that causes the ducts to narrow permitting less blood flow by blocking the effects of prostaglandins.