Effect of the mode of delivery on the risk of endometriosis recurrence: a retrospective cohort study

Objective: To evaluate the risk of endometriosis recurrence according to the mode of delivery (cesarean section vs. vaginal birth) in patients who had become pregnant with a live birth after surgery for endometriosis. Design: A retrospective cohort study. A Cox proportional-hazards regression was performed to evaluate the risk factors for endometriosis recurrence at 36 months of follow-up after the last pregnancy. Setting: Academic hospital. Patient(s): Patients who have had ≥1 pregnancy with a live birth following conservative surgery for ovarian endometriosis performed from January 2009 to December 2016 at our institution. Intervention(s): Patients who underwent ≥1 cesarean section after surgery for endometriosis. Main outcome measures: The recurrence rate of endometriosis after live-birth pregnancies obtained after the first surgery for endometriosis. Results: Patients with a history of ≥1 cesarean section after surgery for endometriosis have a higher risk of endometriosis recurrence than the patients who have had a vaginal birth, with an adjusted hazard ratio of 2.25 (95% confidence interval, 1.27-3.96). Conclusion: A cesarean section after surgery for endometriosis is associated with a twofold high risk of endometriosis recurrence with respect to vaginal birth. A different follow-up approach may be needed in those patients, and avoiding inappropriate indications for cesarean sections in pregnant patients with a history of surgery for endometriosis is necessary.