Patent ductus arteriosus (PDA)

The ductus arteriosus is a normal fetal artery connecting the main body artery (aorta) and the main lung artery (pulmonary artery). The ductus allows blood to detour away from the lungs before birth.

Every baby is born with a ductus arteriosus. After birth, the opening is no longer needed and it usually narrows and closes within the first few days.

Sometimes, the ductus doesn’t close after birth. Failure of the ductus to close is common in premature infants but rare in full-term babies. In most children, the cause of PDA isn’t known. Some children can have other heart defects along with the PDA.