parentage vs birth

parentage and birth both are nouns.

Word	Noun	Adjective	Verb	Adverb
parentage	Yes	No	No	No
birth	Yes	No	Yes	No

As nouns, parentage and birth are synonyms defined as:

parentage and birth: the kinship relation of an offspring to the parents

parentage (noun)	birth (noun)
the hereditary derivation of an individual	the event of being born
the kinship relation of an offspring to the parents	a baby born; an offspring
the state of being a parent	the process of giving birth
	the kinship relation of an offspring to the parents
	the time when something begins (especially life)

parentage (verb)	birth (verb)
	cause to be born