Risk of unscheduled delivery in women with placenta accreta according to planned gestational age at delivery

Background: The optimal gestational age at delivery for stable women with suspected placenta accreta is still subject of debate. Objective: To estimate the likelihood of vaginal bleeding necessitating expedited delivery in women with placenta accreta according to gestational age at planned cesarean hysterectomy. Study design: This was a multicenter cohort study. Singleton pregnancies at risk of placenta accreta because of placenta previa in the setting of prior cesarean delivery were included. Outcomes were compared in cohort of women who had planned cesarean hysterectomy at 34 0/7 - 34 6/7 weeks versus at 35 0/7 - 35 6/7 weeks. The primary outcome was incidence of vaginal bleeding severe enough to necessitate delivery. Results: 118 singleton pregnancies with placenta previa in the setting of prior cesarean delivery, and confirmed placenta accreta at the time of delivery were included in the study. Women who had planned cesarean hysterectomy at 34 weeks had lower episodes of vaginal bleeding severe enough to necessitate immediate or emergency delivery (20.6% vs 38.0%; odds ratio (OR) 0.42, 95% confidence interval (CI) 0.19 to 0.96). Eight women (11.8%) in the 34 weeks group and 6 women (12.0%) in the 35 weeks group delivered before the planned date due to onset of spontaneous labor (OR 0.98, 95% CI 0.32 to 3.02). Conclusion: In singleton gestations with suspected placenta accreta, planned cesarean hysterectomy at 34 0/7 - 34 6/7 weeks was associated with a decreased chance of unscheduled delivery due to severe vaginal bleeding.