Refining the Clinical Definition of Active Phase Arrest of Dilation in Nulliparous Women to Consider Degree of Cervical Dilation As Well As Duration of Arrest

(Am J Obstet Gynecol. 2021;225:294.e1–294.e14) Contemporary duration of labor is slower than historically recorded. Previous studies, including the Consortium on Safe Labor, concluded that 4 hours of oxytocin augmentation may increase vaginal delivery rates without increasing harm to the neonate. Current definitions of arrest of dilation do not examine the degree of cervical dilation and give recommendations for dilation beyond 4 hours. Using the Consortium on Safe Labor’s retrospective cohort study as a guideline, this study aimed to understand the impact on maternal and neonatal outcomes in nulliparous women in the active phase of labor in reference to time needed to achieve cervical dilation of 6, 7, 8, and 9 cm.