patent ductus arteriosis
Patent ductus arteriosis is a congenital heart defect that allows blood to mix between the pulmonary artery and the aorta. Before birth an open passageway (the ductus arteriosus) exists between these two blood vessels, but it closes within a few hours of birth. When this doesn't happen, some blood that should flow through the aorta and out to the body returns to the blood vessels of the lungs. Patent ductus arteriosis is more common in premature infants than full-term babies.
