Analysis of the levonorgestrel-releasing intrauterine system in women with endometriosis

Objectives To compare the efficacy, safety and other clinical benefits of the levonorgestrel-releasing intrauterine system (LNG-IUS) and gonadotropin-releasing hormone analogues (GnRH-a) in women with endometriosis. Methods A systematic search was carried out using the Cochrane Central Register of Controlled Trials, PubMed, MEDLINE and EMBASE databases for all randomized controlled trials (RCTs) that evaluated the use of the LNG-IUS and GnRH-a in premenopausal women with endometriosis. Results Five RCTs studies were identified. A meta-analysis showed that, in women with endometriosis, both the LNG-IUS and GnRH-a reduced pain visual analogue scale scores (weighted mean difference [WMD] 0.03 [95% confidence interval [CI] -0.53, 0.59]), serum levels of CA125 (WMD -12.29 [95% CI -29.90, 3.32]), and American Society of Reproductive Medicine staging scores (WMD 1.10 [95% CI -27.98, 30.18]). Psychological and general wellbeing index scores were increased (WMD 1.50 [95% CI -6.19, 9.19]). Levels of low-density lipoprotein cholesterol were also significantly reduced in patients treated with the LNG-IUS (WMD 39.30 [95% CI 6.74, 71.86]). Conclusions The LNG-IUS had clinical efficacy equivalent to that of GnRH-a but may have some clinical advantages over GnRH-a in the treatment of endometriosis-associated symptoms. These observations will require further verification in additional studies employing larger patient populations.