The effect of oral contraceptives on aromatase expression in the eutopic endometrium of patients with endometriosis.

Objective: To determine the effect of oral contraceptives containing gestodene on aromatase expression in the endometrium of patients diagnosed with endometriosis.

Patients And Methods: Endometrial biopsies were taken at the time of laparoscopy in 40 patients with endometriosis, 16 of whom were using an oral contraceptive containing gestodene at the time of laparoscopy. The remaining 24 patients were receiving no form of treatment for endometriosis. Endometrial biopsies taken from 23 patients with normal echographic signs and no symptoms were used as controls. Aromatase expression was evaluated in endometrial samples using immunohistochemistry.

Results: In the untreated, symptomatic endometriosis patients, aromatase expression was detected during the proliferative phase in 92% of cases, while in the symptom-free control patients aromatase was expressed in only 9% of cases. In patients with endometriosis who were using oral contraceptives, there were significantly fewer cases of positive endometria compared with the untreated patients with endometriosis (6%).

Conclusion: Oral contraceptives containing gestodene are effective in decreasing aromatase expression in the eutopic endometrium of patients with endometriosis.