Effects of Dienogest Therapy on Endometriosis- Related Dysmenorrhea, Dyspareunia, and Endometrioma Size

Introduction: Endometriosis is an estrogen-dependent chronic inflammatory disease that is defined by the presence of endometrial-like tissue outside of the uterus. The most common localization is the ovaries, and endometriosis in this location is then called an endometrioma. According to the European Society of Human Reproduction and Embryology (ESHRE) (2022) guidelines, the most commonly prescribed treatments for endometriosis include drugs that alter the hormonal milieu. Dienogest is a new generation of progestin used in the treatment of endometriosis. The aim of this study was to assess the effect of Dienogest treatment on endometrioma size and endometriosis-related pain symptoms over a six-month follow-up period.Methods: This prospective observational study was conducted at a tertiary clinic in Turkey between March 2020 and March 2021. Here, 64 patients aged 17-49 years with unilateral or bilateral endometriomas without any hormone-dependent cancers and any medical conditions contraindicating the onset of hormonal treatment, such as active venous thromboembolism, previous or current cardiovascular disease, diabetes with cardiovascular complications, current severe liver disease, and not being pregnant, were included. Endometrioma sizes were determined by transvaginal ultrasonography (TVUS). Dysmenorrhea and dyspareunia symptoms were evaluated using the visual analogue scale (VAS). Patients received Dienogest 2 mg/day continuously for six months. At the three-and six-month follow-ups, the patients were re-evaluated.Results: The mean endometrioma size decreased significantly from an initial measurement of 44.0 +/- 13 mm to 39.5 +/- 15 mm at three months and to 34.4 +/- 18 mm at the six-month follow-up. The mean dysmenorrhea VAS scores before treatment, at the three-month follow-up, and at the six-month follow-up were 6.9 +/- 2.6, 4.3 +/- 2.8, and 3.8 +/- 2.7, respectively. Dysmenorrhea VAS scores decreased significantly over the first three months (p<0.01). Similarly, the mean VAS score for dyspareunia decreased at three and six months compared with the pretreatment value (p<0.01).Conclusion: This study shows that dienogest treatment reduced the symptoms of dysmenorrhea and dyspareunia and the size of endometriomas. However, the main significant decrease in dysmenorrhea and dyspareunia symptoms was noted in the first three months, making it a good treatment option, especially in young patients with a fertility wish.