Randomized controlled trial of labor outcomes with action line placement at 2 hours versus 4 hours on the partograph.

Objective: To evaluate whether treatment of slow labor progress among term nulliparous women using a 2-hour partograph action line reduces the incidence of prolonged labor versus a 4-hour action line.

Methods: Randomized controlled trial of nulliparous women with a term singleton, non-macrosomic, cephalic fetus in labor attending a university hospital in Nigeria (2008-2015). For labor supervision, women were randomly assigned to the 2-hour (n=320) or 4-hour (n=320) partograph action line group.