Abnormal development of a body part during the life of the embryo or fetus, usually but not always apparent at or soon after birth. It can be genetically inherited or be acquired by exposure to a physical or chemical insult, such as the action of a teratogen (a drug or other substance in the environment), during development in the mother's uterus. Few congenital abnormalities can be associated with a specific cause, and an apparent cause might not be the true one.

An abnormality present at birth, although not necessarily hereditary.

a defect that is present at birth

a condition that has been passed on through genetics

a problem present at birth (see birth defects).

Any abnormality which is present at birth. Also called birth defects, they can arise from genetic inheritance or acquired during gestation through disease or drugs.