Final answer:
A rapid fall below 100 bpm during contractions indicates variable decelerations, often linked to cord compression.
Step-by-step explanation:
The question pertains to the interpretation of fetal heart rate patterns during labor. A rapid fall below 100 beats per minute at any time during contractions typically indicates variable decelerations. Variable decelerations are characterized by abrupt decreases in fetal heart rate with a rapid descent and ascent, usually associated with cord compression. It is different from early decelerations, which are associated with head compression during contractions and mirror the contraction pattern, or from late decelerations, which are associated with uteroplacental insufficiency and begin after the start of a contraction and return to baseline after the contraction ends.