Long-term treatment of endometriosis-related pain among women seeking hormonal contraception.

Objective: To evaluate the different effects of a progestin-only contraceptive with desogestrel (DSG) vs combined oral contraceptives (COCs) for a first line long-term treatment of endometriosis-related pain among patients seeking hormonal contraception.
Methods: An observational retrospective cohort study was conducted in collaboration with a local outpatient clinic for endometriosis among a group of nulliparous young women ( n  = 216) with endometriosis-related pain and seeking contraception. The cohort was subdivided into a group ( n  = 73) treated as first line by DSG and another group ( n  = 75) treated by a COC. During the study, clinical symptoms, side effects and possible changes in OC type use were recorded.
Results: No significant difference was found between the two groups in terms of clinical characteristics and pain scores before treatment. After 6 months both treatments were effective in reducing endometriosis-related pain, and those treated with DSG showed lower levels of dysmenorrhea, dyspareunia and nonmenstrual pelvic pain than COCs group ( p  < .01). After 12 months, in DSG Group some patients (15%) switched from DSG to a COC for breakthrough bleeding, whereas in COC Group 48% of patients switched to another type of COC for reduced efficacy on pain and/or for side effects. After 3 years of OC treatment, in DSG Group 79% of patients maintained the same therapy, whereas in COC Group only 14% continued the same COC type, 37% switched to another COC and 47% to DSG.
Conclusions: A progestin-only contraceptive with DSG is a valid option for long term management of endometriosis-related pain in patients seeking hormonal contraception.