Perinatal Outcomes in the Setting of Active Phase Arrest of Labor

Abstract

Diagnosis of active phase arrest has been defined as no cervical change for a minimum of 2 hours in the setting of an adequate uterine contraction pattern. However, cesarean deliveries performed for active phase arrest often fail to meet these criteria. Previous studies have demonstrated that a majority of women diagnosed with active phase arrest will achieve a vaginal delivery if given at least 4-hours before a diagnosis of active phase arrest is made. These studies also showed low rates of maternal and neonatal complications among all women with active phase arrest, and similar rates for cesarean and vaginal deliveries. To confirm these findings, this retrospective cohort study evaluated perinatal outcomes in Californian women with a live, term, cephalic, singleton birth who were diagnosed with active phase arrest of labor for at least 2-hours and delivered between 1991 and 2001 (n = 1014). Two comparisons were made. In the first, rates of adverse perinatal outcomes among women with active phase arrest were compared by mode of delivery: vaginal or cesarean. In the second, outcomes of women who delivered vaginally were compared in those with or without active phase arrest. Of the 1014 women identified with active phase arrest, 33% (335) went on to deliver vaginally, and 68% (679) underwent cesarean deliveries. Among these women, multivariable logistic regression analysis showed that cesarean delivery was associated with an increased risk of chorioamnionitis (adjusted odds ratio [aOR] 3.37, 95% confidence interval [CI] 2.21–5.15), endomyometritis (aOR 48.41, 95% CI 6.61–354), postpartum hemorrhage (aOR 5.18, 95% CI 3.42– 7.85), and severe postpartum hemorrhage (aOR 14.97, 95% CI 1.77–126). There was no significant association between cesarean delivery and adverse neonatal outcomes in women with active phase arrest. Women with active phase arrest who delivered vaginally had significantly increased odds of chorioamnionitis (aOR 1.78, 95% CI 1.22–2.36) and shoulder dystocia (aOR 2.37, 95% CI 1.33– 4.25). There were no differences in rates of other adverse neonatal outcomes and active phase arrest, including sepsis, neonatal intensive care unit admission, clavicular fracture, Erb’s palsy, and acidemia. These findings suggest to the investigators that an attempt to achieve vaginal delivery in women diagnosed with active phase arrest should be made because it poses no additional risk to the neonate and may reduce the maternal risks associated with cesarean delivery.