P-308 Relationship Between Anti-Mullerian Hormone Levels and Age in Women with Endometriosis: A Population-Based Study

Abstract Study question What is the relationship between age and Anti-Mullerian Hormone (AMH) levels in women with and without endometriosis? Summary answer AMH levels decreased with age in both groups, but declined consistently in women with endometriosis, while controls showed a threshold at 27 years. What is known already AMH levels in women with endometriosis are lower than in healthy controls. While previous studies have shown an association between AMH levels and endometriosis, there is no data on the relationship between AMH levels and age among women with endometriosis. Study design, size, duration This is a population-based, cross-sectional study using data from the 6th follow-up visit of the Tehran Lipid and Glucose Study. A total of 1,005 reproductive-age women were included, with 305 women diagnosed with endometriosis and 700 controls. Participants/materials, setting, methods Participants included 1,005 reproductive-age women (305 with endometriosis and 700 controls) selected from the 6th follow-up visit of the Tehran Lipid and Glucose Study. AMH serum concentrations were measured for both groups. The relationship between age and AMH levels was visualized using scatterplots with quadratic regression lines for each group. Segmented regression analysis was employed to identify potential breakpoints in the relationship between age and AMH levels in both women with endometriosis and controls. Main results and the role of chance A total of 1,005 women aged 18–48 years participated in the study, including 305 (30.3%) with endometriosis and 700 (69.7%) healthy controls. Women with endometriosis had significantly lower AMH levels compared to healthy controls (1.99±1.42 vs. 2.30±1.61 ng/ml; P = 0.029). In healthy controls, AMH levels declined with age at a slope of − 0.15 (95% CI: −0.17, −0.14; P < 0.001). Segmented regression identified a threshold at 27 years (1.92), with a sharper decline below this age (slope: −0.35, 95% CI: −0.47, −0.23; P < 0.001) and a more gradual decline beyond it (slope: −0.12, 95% CI: −0.14, −0.10; P < 0.001). In women with endometriosis, AMH levels also declined with age (slope: −0.16, 95% CI: −0.17, −0.14; P < 0.001), with no significant threshold observed. Limitations, reasons for caution lack of comprehensive assessment of all endometriosis cases through laparoscopy, which is considered the gold standard for definitive diagnosis of this condition, the absence of AFC measurements, which could have provided a more comprehensive evaluation of ovarian reserve, cross-sectional design limits causal inferences. Wider implications of the findings This study highlights the need for alternative markers, such as antral follicle count (AFC), to assess ovarian reserve in women with endometriosis, as AMH levels may not accurately reflect age-related changes in this population. These findings could inform clinical practices in fertility management and personalized care strategies. Trial registration number No