Congenital defects are malformations of the heart or major blood
vessels which are caused by abnormal development of the fetus and which
are present at birth. Some are the consequences of German measles
(Rubella) or exposure to chemical poisons during pregnancy.
The most common defects are holes in the wall dividing the right side from
the left side of the heart (septal defects). They can usually be detected at birth by
the heart murmur that they cause. Others may require complex tests for accurate
diagnosis and these may have to wait until the infant is a few months old. Again, the great progress in recent years in cardiovascular surgery has
made it possible to correct many of these defects surgically.