The effect of dienogest treatment on anti-Mullerian hormone in patients with endometrioma: a 12-month follow-up study.

Objective: To assess the effect of dienogest treatment on endometrioma (OMA) size, serum anti-Mullerian hormone (AMH) levels and associated pain over a 12-month follow-up period.

Material and methods: A longitudinal cohort study of 104 patients with OMA who were treated with dienogest, between January 2017 and January 2020. Of the included patients, each had a 12-month follow-up period with transvaginal or pelvic ultrasound and measurement of serum AMH concentration at the sixth and twelfth months of follow-up. The alteration in OMA size in the sixth and twelfth months of treatment was the primary outcome measure and the alteration in AMH concentration over the same period was the secondary outcome measure. The only exclusion criterion was having surgical intervention for OMA during the follow-up period (n=44). In patients with bilateral OMA (n=21), the change in size of the largest OMA was considered in the analysis.

Results: A total of 60 patients with a mean ± standard deviation (SD) age of 31.5±8.0 years were included. The mean ± SD OMA size on the day the dienogest was started was 46.3±17.4 mm and the mean AMH level was 3.6±2.4 ng/mL. After six months, the mean OMA size had decreased to 38.6±14.0 mm, with a median difference of 7.8 mm [95% confidence interval (CI): 3.0 to 12.6; p=0.003]. The mean AMH level was 3.3±2.7 ng/mL at 6 months follow-up (95% CI: -0.2 to 0.8; p=0.23) and the average difference was 0.3 ng/mL. At the 12^th-month visit, when compared with the beginning of the treatment, OMA size had again significantly decreased by a median of -8.9 mm (95% CI: -2.9 to -14.9; p=0.005), and the decline in median AMH was also significant (-0.9 ng/mL, 95% CI: -0.1 to -1.7; p=0.045). The initial mean ± SD visual analog scale pain score at the commencement of dienogest treatment was 6.3±3.4. The mean values at the sixth and twelfth months of dienogest therapy were 1.08±1.8 and 0.75±1.5, respectively (both p<0.001 compared to baseline).

Conclusion: At the sixth and twelfth months of dienogest treatment a significant decrease in OMA size and reported pain scores were observed, whereas the AMH concentrations did not change significantly.