Long-term cyclic and continuous oral contraceptive therapy and endometrioma recurrence: a randomized controlled trial.

OBJECTIVE: To evaluate long-term cyclic and continuous administration of oral contraceptive pills (OCP) in preventing ovarian endometrioma recurrence after laparoscopic cystectomy. DESIGN: Prospective, randomized, controlled trial. SETTING: Tertiary care University Hospital. PATIENT(S): Two hundred thirty-nine women who underwent laparoscopic excision of ovarian endometriomas. INTERVENTION(S): Patients were divided randomly into three groups: nonusers receiving no therapy and cyclic and continuous users receiving low-dose, monophasic OCP for 24 months in cyclic or continuous administration, respectively. MAIN OUTCOME MEASURE(S): Endometrioma recurrence, size of recurrent endometrioma, and growth rate during at least 2 years follow-up evaluated by transvaginal ultrasonography. RESULT(S): The crude recurrence rate within 24 months was significantly lower in cyclic (14.7%) and continuous users (8.2%) compared with nonusers (29%). The recurrence-free survival was significantly lower in nonusers compared with cyclic and continuous users. The mean recurrent endometrioma diameter at first observation was significantly lower in cyclic (2.17 +/- 0.45 cm) and continuous users (1.71 +/- 0.19 cm) compared with nonusers (2.73 +/- 0.56 cm). The mean diameter increase every 6 months of follow-up was significantly reduced in cyclic users (0.31 +/- 0.18 cm) and continuous users (0.25 +/- 0.09 cm) versus nonusers (0.48 +/- 0.3 cm). No significant differences between cyclic users and continuous users in terms of endometrioma recurrence were demonstrated. CONCLUSION(S): Long-term cyclic and continuous postoperative use of OCP can effectively reduce and delay endometrioma recurrence.