“Active Labor” Duration and Dilation Rates Among Low-Risk, Nulliparous Women With Spontaneous Labor Onset: A Systematic Review

These findings indicate that nulliparous women with spontaneous labor onset have longer “active” labors and therefore slower dilation rates than are traditionally associated with active labor when commonly used criteria are applied as the starting point. Revision of existing active labor expectations and/or criteria used to prospectively identify active phase onset is warranted.