Final answer:
The term 'Premature rupture of membranes (PROM)' refers to the spontaneous break of the amniotic sac before the onset of labor contractions.
Step-by-step explanation:
The correct answer to the question "Premature rupture of membranes (PROM) is a ________ break in the amniotic sac __________ the _________ of contractions." is a) spontaneous, before, onset. This refers to the spontaneous breaking of the amniotic sac before the onset of labor contractions. During the process of childbirth, if the amniotic sac breaks before labor has started, it is known as PROM. The breakage of the amniotic sac may result in a gush of fluid, commonly described by women saying that their "water broke". Labor usually begins within a day of this event but may start sooner.