The prognosis of unchanged cervical dilation in active labor during labor induction

OBJECTIVE: The most common indication for cesarean delivery (CD) in the United States is failure to progress, with a large portion of these cases occurring in the setting of active labor dystocia. There is a current lack of data to guide counseling on the likelihood of requiring CD and associated maternal outcomes in the setting of unchanged cervical dilation in the active phase. STUDY DESIGN: This is a retrospective cohort study of nulliparous patients with term singleton pregnancies who underwent induction of labor and progressed to active labor at a single institution between 1/1/2019-12/31/2019. Outcomes were compared among: (1) all who reached active labor, (2) active labor dystocia ≥2 hours, and (3) active labor dystocia ≥4 hours. The primary outcome was CD for any indication, with secondary outcomes of composite maternal morbidity and neonatal morbidity. RESULTS: Among 1309 eligible inductions, 1095 (83.7%) reached active labor and were included. Those with dystocia ≥2 hours and dystocia ≥4 hours had significantly higher risk of requiring a neonatal morbidity. CD (52.6% and 82.0%, respectively) when compared to those who reached active labor but did not experience dystocia (CD rate: 15.4%, p<0.001). Composite maternal morbidity also increased by increasing length of labor dystocia. There were no significant findings pertaining to Conclusion: CD and maternal morbidity rates are significantly higher in nulliparous patients experiencing active labor dystocia, even at the 2h mark. These findings should inform counseling around CD risk as labor progresses.