Dual effects of anti-Müllerian hormone on ovarian response and fertilization in assisted reproductive technology cycles: a retrospective cohort study.

OBJECTIVE: To investigate the dual effects of anti-Müllerian hormone (AMH) on ovarian response, fertilization outcomes, and clinical pregnancy in assisted reproductive technology (ART) cycles. METHODS: This retrospective cohort study screened 6,312 in vitro fertilization or intracytoplasmic sperm injection cycles performed between 2018 and 2023. After excluding cycles with missing AMH or body mass index (BMI) values, non-ART cycles, and extreme BMI values (<18 or ≥45 kg/m2), 4,399 cycles were included. AMH level, age, and BMI were evaluated as independent variables. Ovarian response (retrieved oocyte count) and normally fertilized embryos (two pronuclei) were analyzed using multivariable linear regression, and clinical pregnancy was evaluated using logistic regression. RESULTS: AMH level showed a strong positive association with ovarian response (β=2.348; P<0.001), whereas age showed a significant negative association. After adjusting for age, BMI, fertilization method, and retrieved oocytes, AMH level showed a small but significant negative association with fertilized embryo count (β=-0.044; P=0.027). In the subgroup analysis, cycles with AMH ≥10 ng/mL showed higher oocyte yield but lower fertilization (0.561 vs. 0.694; P<0.001) and clinical pregnancy rates (5.7% vs. 23.1%; P<0.001) than those with AMH <10 ng/mL. Increasing age and AMH levels were independently associated with reduced odds of clinical pregnancy. CONCLUSION: AMH may reflect ovarian reserve quantity rather than optimal reproductive potential, showing a positive association with oocyte yield, but a negative association with fertilization and clinical pregnancy outcomes in ART cycles.