Defining and Managing Normal and Abnormal First Stage of Labor.

Modern data have redefined the normal first stage of labor. Key differences include that the latent phase of labor is much slower than was previously thought and the transition from latent to active labor does not occur until about 6 cm of cervical dilatation, regardless of parity or whether labor was spontaneous or induced. Providers should have a low threshold to use one of the safe and effective interventions to manage abnormal progression in the first stage of labor, including oxytocin, internal tocodynamometry, and amniotomy.