A recent study issued in the 'European Journal of Obstetrics & Gynecology and Reproductive Health' stated that there is a positive effect of the levonorgestrel-releasing intrauterine system (LNG-IUS) as postoperative maintenance therapy for endometriosis on pain relief, prevention of dysmenorrhea recurrence, and on patients' satisfaction.

This meta-analysis was performed to distinguish the efficacy of LNG-IUS with other treatments as postoperative maintenance therapy for endometriosis for pain reduction, recurrence prevention, side effects and patients' satisfaction. Soo Youn Song and the team searched MEDLINE, EMBASE, and the Cochrane Library from January 1986 until February 2018. The predetermined selection criteria were used by two evaluators to extract and review the prospective and retrospective articles. The outcomes were portrayed as mean difference (MD), risk ratios (RR) or odds ratios (OR) in a meta-analysis model, using Revman software. Out of a total of 962 studies, 7 studies were selected. These 7 studies included 4 randomized controlled trials comprising 212 patients, 1 prospective cohort study involving 88 patients, and 2 retrospective studies involving 191 patients.  It was revealed that LNG-IUS was significantly effective in reducing pain after surgery with a comparable effect to gonadotropin-releasing hormone analogues. The LNG-IUS was also effective in reducing the recurrence rate (RR = 0.40, 95% CI: 0.26–0.64), with an effect corresponding to OC and danazol. Also, the patients' satisfaction with LNG-IUS was significantly more than that with OC (OR = 8.60, 95% CI: 1.03–71.86). But, the vaginal bleeding was significantly higher in the LNG-IUS group than in the gonadotropin-releasing hormone analogue group.