RESUMEN
BACKGROUND: Medical treatment of endometriosis, a condition which significantly affects the quality of life in approximately 10-15% of women in the reproductive years, remains problematic. Although oral progestogens are effective and cheap, their efficacy is significantly influenced by poor compliance and systemic side effects. A progestogen (levonorgestrel) administered via an intrauterine system (Lng-IUS) has been demonstrated to improve symptoms of endometriosis; however, its effect on the staging of the disease has not been evaluated. The aims of this study were therefore to investigate the effectiveness of Lng-IUS in the symptomatic relief of minimal to moderate endometriosis and in the staging of the disease. METHODS: This was a prospective non-comparative observational study in which 34 women with clinically suspected and laparoscopically confirmed symptomatic minimal to moderate endometriosis had Lng-IUS inserted for 6 months. The symptom profile and stage of the disease before, during and after 6 months of treatment and patients' satisfaction with treatment and willingness to retain the device at the end of the study period were used to assess response to treatment. RESULTS: Of the 34 women recruited, 29 (85%) completed the study; five discontinued, for personal reasons (one), side effects of worsening of acne (one) and lower abdominal/ pelvic pain (three). Significant (P<0.05) improvements in severity and frequency of pain and menstrual symptoms as well as staging were achieved, with 68% (23) of cases electing to continue with the device after 6 months of therapy. CONCLUSION: The levonorgestrel intrauterine system is an effective hormonal option for treating symptomatic endometriosis (minimal to moderate). It also alters the American Fertility Society staging of disease. With a continuation rate of 68% after 6 months, it has the potential for providing long-term therapy in a substantial number of sufferers, although this would require further study and verification.