premature labor vs parturiency

premature labor and parturiency both are nouns.

Word	Noun	Adjective	Verb	Adverb
premature labor	Yes	No	No	No
parturiency	Yes	No	No	No

As nouns, parturiency is a hypernym of premature labor; that is, parturiency is a word with a broader meaning than premature labor:

premature labor: labor beginning prior to the 37th week of gestation
parturiency: concluding state of pregnancy; from the onset of contractions to the birth of a child

Other hypernyms of premature labor include childbed, confinement, labor, labour, lying-in, travail.

premature labor (noun)	parturiency (noun)
labor beginning prior to the 37th week of gestation	concluding state of pregnancy; from the onset of contractions to the birth of a child