Postoperative oral contraceptive exposure and risk of endometrioma recurrence

Objective: The purpose of this study was to compare the postoperative risk of endometrioma recurrence in women using oral contraception and in those undergoing simple observation. Study Design: After laparoscopic excision of ovarian endometriotiomas, a cyclic, low-dose, monophasic oral contraceptive pill (OCP) was offered to women not seeking pregnancy. One month after surgery, and every 6 months afterward, the patients underwent clinical and ultrasonographic assessment. Results: Of the 277 patients who entered the study, 102 used OCP for the entire follow-up period (always users), 129 used OCP discontinuously (ever users), and 46 declined treatment (never users). The median follow-up was 28 months. Recurrent endometriotic cysts were detected in 74 subjects (27%). The 36-month cumulative proportion of subjects free from endometrioma recurrence was 94% in the always users compared with 51% in the never users (P < .001); adjusted incidence rate ratio (IRR) = 0.10 (95% CI, 0.04-0.24). Conclusion: Regular postoperative use of OCP effectively prevents endometrioma recurrence.