A key differentiating factor when determining if a deceleration is early or late is the

Comprehensive and Detailed Explanation From Exact Extract (NCC-Referenced Sources)

AWHONN and Menihan clearly state that classification of decelerations is determined by their timing relative to uterine contractions:

Early decelerations: “mirror the contraction; onset, nadir, and recovery occur simultaneously with the contraction.”

Late decelerations: “begin after the contraction begins and return to baseline after the contraction ends.”

Depth is not a differentiating feature, as both early and late decelerations may vary in depth. The onset-to-nadir interval is used to differentiate variable vs. early/late, not early vs. late.

Thus, timing relative to contractions is the correct NCC-supported answer.