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.