happy event vs live birth

happy event and live birth both are nouns.

Word	Noun	Adjective	Verb	Adverb
happy event	Yes	No	No	No
live birth	Yes	No	No	No

As nouns, live birth is a hypernym of happy event; that is, live birth is a word with a broader meaning than happy event:

happy event: the live birth of a child
live birth: the birth of a living fetus (regardless of the length of gestation)

happy event (noun)	live birth (noun)
the live birth of a child	the birth of a living fetus (regardless of the length of gestation)