According to the American Heart Association, about eight of every
1,000 babies born in the United States has a congenital heart defect
(present at birth)—a problem that occurred as the baby's heart was
developing during pregnancy, before the baby is born. Congenital heart
defects, also called congenital heart diseases, are the most common
A baby's heart begins to develop at conception, but is completely
formed by eight weeks into the pregnancy. Congenital heart defects
happen during this crucial first eight weeks of the baby's
development. Specific steps must take place in order for the heart to
form correctly. Often,congenital heart disease is a result of one of
these crucial steps not happening at the right time, leaving a hole
where a dividing wall should have formed, or a single blood vessel
where two ought to be, for example.
Rarely, defects include those in which:
The right or left side of the heart is incompletely formed and
is called hypoplastic heart.
Only one ventricle is
Both the pulmonary artery and aorta arise from the
The pulmonary artery and aorta arise from
the "wrong" ventricles.