Comment: The level of evidence is downgraded by study quality (unclear allocation concealment and blinding) and imprecise results (few patients).
A Cochrane review «Progestogens or progestogen‐releasing intrauterine systems for uterine fibroids (other than preoperative medical therapy)»1 «...»1 included 4 studies with a total of 221participants. There was a significant reduction of menstrual blood loss (MBL) in women receiving the LNG-IUS compared to the combined oral contraceptives using the alkaline hematin test (mean difference (MD) 77.5%, 95% CI 71.3% to 83.67%; n=44) and a pictorial assessment chart (MD 34.5%, 95% CI 12% to 57.1%; n=44). Compared with norethisterone acetate, LNG-IUS reduced MBL (visual bleeding score; MD 23.75 points, 95% CI 1.26 to 46.24; 1 RCT, n=45) and increased haemoglobin.
A systematic review «Jiang W, Shen Q, Chen M et al. Levonorgestrel-rele...»2 evaluated the efficacy and safety of LNG-IUS in premenopausal women with symptomatic uterine leiomyoma. 11 studies were included. LNG-IUS significantly reduced menstrual blood loss, and increased blood haemoglobin, ferritin and hematocrit levels. There was a trend towards decreased uterine volume and endometrial thickness. Uterine leiomyoma volume did not decrease. There were no adverse effects on the ovarian function except for ovarian cysts. Device expulsion rates were low.