Friedman labor curve

First stage = A + B + C + D, where A = latent phase, B = acceleration phase, C = phase of maximum slope, and D = deceleration phase.
Second stage = E.

Data from: Friedman EA. Labor: Clinical evaluation and management, 2nd ed, Appleton-Century-Crofts, New York 1978.

Graphic 53413 Version 4.0