Levonorgestrel-releasing intrauterine system or medroxyprogesterone for heavy menstrual bleeding: a randomized controlled trial.

OBJECTIVE To compare the efficacy and safety of the levonorgestrel-releasing intrauterine system and oral medroxyprogesterone acetate in the treatment of idiopathic heavy menstrual bleeding. METHODS In this multicenter, randomized, controlled study, women aged 18 years or older with heavy menstrual bleeding (menstrual blood loss 80 mL or more per cycle) were randomly assigned to six cycles of treatment with either levonorgestrel-releasing intrauterine system or oral medroxyprogesterone acetate (10 mg daily for 10 days beginning on day 16 of each cycle). The primary efficacy variables were the absolute change in menstrual blood loss from baseline to end of study and the proportion of women with successful treatment (defined as menstrual blood loss less than 80 mL and a 50% or greater reduction in menstrual blood loss from baseline). RESULTS Of 807 women screened, 165 were randomly assigned to treatment (levonorgestrel-releasing intrauterine system n=82, oral medroxyprogesterone acetate n=83). At the end of the study, the absolute reduction in median menstrual blood loss was significantly greater in the levonorgestrel-releasing intrauterine system group (-128.8 mL, range -393.6 to +1242.2 mL) than in the medroxyprogesterone acetate arm (-17.8 mL, range -271.5 to +78.6 mL, P < .001), and the proportion of women with successful treatment was significantly higher for the levonorgestrel-releasing intrauterine system (84.8%) than for medroxyprogesterone acetate (22.2%, P < .001). CONCLUSION In women with idiopathic heavy menstrual bleeding, the levonorgestrel-releasing intrauterine system reduces menstrual blood loss more effectively and has a higher likelihood of treatment success than oral medroxyprogesterone acetate. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, www.clinicaltrials.gov, NCT00360490. LEVEL OF EVIDENCE I.