Factors influencing preoperative AMH levels in women with ovarian endometrioma

Ovarian endometrioma is a common ovarian cyst in women with endometriosis, often causing pelvic pain and infertility and potentially impairing ovarian reserve. Anti-Mullerian Hormone (AMH) is a reliable serum marker of ovarian reserve, yet its relationship with baseline clinical characteristics remains inadequately explored. This retrospective study included 576 patients who underwent laparoscopic surgery for ovarian endometrioma between January 2021 and March 2025. We analyzed clinical age, parity, BMI, cyst features, postoperative rASRM stage, and preoperative AMH using SPSS 27.0. Among the 576 enrolled patients, the median preoperative AMH level was 2.45 ng/mL. Age was strongly negatively correlated with AMH ( P < 0.001), with median AMH declining from 3.23 ng/mL in patients < 25 years to 0.66 ng/mL in those ≥ 40 years. Nulliparous patients had a higher median AMH (2.79 ng/mL) than parous ones (1.41 ng/mL) ( P < 0.001). BMI was also negatively associated with AMH ( P < 0.001), with underweight patients having the highest median AMH (2.88 ng/mL). Regarding cyst-related features, bilateral cysts were linked to lower AMH (2.12 ng/mL) compared to unilateral cysts (2.50 ng/mL) ( P = 0.038); postoperative rASRM stage was strongly correlated with AMH ( P < 0.001), with stage IV patients having the lowest median AMH (1.98 ng/mL). Notably, no significant associations were found between AMH and dysmenorrhea ( P = 0.134) or cyst size ( P = 0.579). In the multivariable logistic regression model (AUC = 0.841), only age remained independently associated with low AMH (OR = 1.265, 95% CI 1.190–1.344, P < 0.001), whereas parity, BMI, cyst laterality, postoperative rASRM stage, and dysmenorrhea were no longer significant after adjustment, indicating that their univariate associations were largely confounded by age. Continuous lnAMH analysis confirmed age as the strongest factor, with a possible nonlinear component, and bootstrap validation supported the robustness of the age association. In this retrospective cohort, age was the factor most strongly associated with low preoperative AMH. After adjustment, parity, BMI, cyst laterality, and postoperative rASRM stage were no longer independently associated. Given the observational design, these findings are exploratory and should only inform hypothesis-generating discussions regarding preoperative counseling and fertility preservation.