congenital abnormality vs birth defect

congenital abnormality and birth defect both are nouns.

Word	Noun	Adjective	Verb	Adverb
congenital abnormality	Yes	No	No	No
birth defect	Yes	No	No	No

As nouns, congenital abnormality and birth defect are synonyms defined as:

congenital abnormality and birth defect: a defect that is present at birth

Other synonyms of congenital abnormality include congenital anomaly, congenital defect, congenital disorder.

congenital abnormality (noun)	birth defect (noun)
a defect that is present at birth	a defect that is present at birth