Levonorgestrel-releasing intrauterine system (Mirena) and Depot medroxyprogesterone acetate (Depoprovera) as long-term maintenance therapy for patients with moderate and severe endometriosis: a randomised controlled trial.

Background:  Progestogen therapy has been found to be useful in controlling endometriosis. For patients after conservative surgery, long-term medical maintenance therapy should be sought to prevent recurrence and control symptoms. Levonorgestrel-releasing intrauterine system (LNG-IUS) may be a useful form of prolonged progestogen therapy for endometriosis. Aims:  To evaluate and compare the efficacy and safety of LNG-IUS to depot medroxyprogesterone acetate (MPA) for patients with moderate or severe endometriosis following conservative surgery, in terms of symptoms control, recurrence prevention and patients’ acceptance. Methods:  A total of 30 patients after conservative surgery for endometriosis underwent randomisation. Of these patients, 15 received LNG-IUS and 15 had three-monthly depot MPA for three years. Their symptom control, recurrence, compliance and change in bone mineral density (BMD) were compared. The data were analysed using student’s t-test and chi-square test. Results:  Symptoms and recurrence were controlled by both therapies. The compliance was better in LNG-IUS Group with 13 patients staying on their therapy versus seven patients in Depot MPA Group. LNG-IUS users had a significantly better change in BMD (+0.023, +0.071 g/cm2) than Depot MPA users (−0.030, −0.017 g/cm2) in both hip and lumbar regions. Conclusions:  Levonorgestrel-releasing intrauterine system was effective in symptom control and prevention of recurrence. LNG-IUS users showed a better compliance. After three years, bone gain was noted with LNG-IUS, but bone loss with depot MPA.