Comparative study on the effects of combined oral contraceptives and dienogest in women with endometriosis‑associated chronic pelvic pain.

Objective: To compare the effects of five combined oral contraceptives (COCs) - ethinylestradiol (EE) 30 μg/dienogest (DNG) 2 mg, EE 20 μg/drospirenone (DRSP) 3 mg, 17β-estradiol (E2) 1.5 mg/nomegestrol acetate (NomAc) 2.5 mg,estetrol (E4) 15 mg/DRSP 3 mg and estradiol valerate (E2V)/DNG - and DNG 2 mg daily in women with endometriosis-associated chronic pelvic pain (CPP), dysmenorrhea and dyspareunia.

Study Design: This study was performed from October 2018 to March 2023. A database was set up to collect data from women in each of the six treatment groups. The level of endometriotic pain was measured using a visual analogue scale (VAS). Follow-up was performed at 3 and 6 months.

Results: The intragroup analysis showed an improvement in the VAS score from baseline to 6-month follow-up for each group (p < 0.001). Intergroup analysis showed that women on COCs containing E2 or E4 had a greater improvement in CCP than women on COCs containing EE (at 3 months, p ≤ 0.001; at 6 months, p ≤ 0.009). Women on E4 15 mg/DRSP 3 mg showed a similar improvement to women on DNG at both 3- and 6-month follow-up, and greater improvement compared with women on COCs containing E2 at 6-month follow-up (p = 0.02). Greater improvement in dysmenorrhea and dyspareunia was seen in women on COCs containing E2 and E4, and DNG compared with women on COCs containing EE (p ≤ 0.001).

Conclusions: COCs containing E2 or E4 could be a better treatment for women with endometriosis-associated pain than COCs containing EE. They may represent a suitable alternative to the use of DNG, particularly for women who do not want to become pregnant.