Effects of Endometriosis on Anti-Müllerian Hormone

Background/Objectives: As the population of women with endometriosis increases, approximately 10% of those of reproductive age experience symptoms such as pelvic pain, painful menstruation, and infertility. Individuals with endometriosis usually undergo multiple surgeries due to the high recurrence rate of the condition. However, ovarian surgery tends to reduce the ovarian reserve, presenting a dilemma when deciding whether to recommend surgery or medical treatment for women of reproductive age. The impact of endometriomas on the residual volume of ovarian tissue remains controversial, and it is unclear whether endometriosis itself or endometriomas are the primary problem. In this study, we aimed to investigate whether women with endometriosis have lower levels of anti-Müllerian hormone than women with healthy ovaries before treatment initiation. Methods: A total of 298 participants enrolled in the endometriosis cohort at Severance Hospital, Korea, from 1 October 2020 to 1 July 2024 were included in this study. Of these, 63 participants were from a retrospective study, and 235 were from a prospective study. Due to the use of different assay methods between the reference values and anti-Müllerian hormone measurements from Severance Hospital, a correction was applied using the regression equation. The mean anti-Müllerian hormone levels for individuals with endometriosis were corrected with the regression equation and compared to those of the reference group for each age group using a one-sample t-test. Results: Anti-Müllerian hormone levels decreased with age in the endometriosis group. When comparing mean anti-Müllerian hormone concentrations between the endometriosis group and reference values, among 168 participants aged 20-31 years, the corrected mean anti-Müllerian hormone concentration was 5.96 ± 3.22 ng/mL, higher than the reference value of 4.94 ± 0.17 ng/mL (p < 0.01). Among 31 participants aged 35-37 years, the corrected average anti-Müllerian hormone value was 4.33 ± 3.06 ng/mL, compared to the reference anti-Müllerian hormone level of 3.22 ± 0.15 ng/mL (p = 0.05). There were no significant differences in corrected anti-Müllerian hormone levels between the 32-34-, 38-40-, 41-43-, and ≥44 years age groups. Conclusions: Patients with endometriosis, especially those aged 20-31 years, tended to have higher anti-Müllerian hormone levels than did individuals with healthy ovaries. In other age groups, there were no differences. Given that these levels do not differ significantly across age groups, it is difficult to conclude that patients with endometriosis have a reduced ovarian reserve.