“The ductus arteriosus is a normal fetal artery connecting the 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 Patent Ductus Arteriosus-PDA isn’t known. Some children can have other heart defects along with the PDA.

Truncus arteriosus occurs when the two large arteries carrying blood away from the heart don’t form properly and one large artery is present instead. This artery (the truncus) sits over a large opening or hole in the wall between the two pumping chambers (ventricular septal defect). With only one artery, there is no specific path to the lungs for oxygen before returning to the heart to deliver oxygen to the body.”

American Heart Association-AHA   (www.heart.org/en/health-topics/congenital-heart-defects/about-congenital-heart-defects)