premature labour vs childbed

premature labour and childbed both are nouns.

Word	Noun	Adjective	Verb	Adverb
premature labour	Yes	No	No	No
childbed	Yes	No	No	No

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

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

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

premature labour (noun)	childbed (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