Age- and BMI-stratified assessment of serum anti-Müllerian hormone as a biomarker for polycystic ovary syndrome diagnosis in Chinese women

BACKGROUND: This study aimed to establish the diagnostic cut-off value of serum Anti-Müllerian Hormone (AMH) for Polycystic Ovary Syndrome (PCOS) in Chinese women of reproductive age and explore its diagnostic efficacy, particularly in relation to age, body mass index, and PCOS phenotypes. METHODS: A prospective case-control study was conducted in 264 PCOS patients and 190 healthy controls from December 2021 to December 2023. Serum AMH levels were measured, and Receiver Operating Characteristic curves were plotted to assess diagnostic efficacy. PCOS was classified into four phenotypes based on Rotterdam criteria. RESULTS: Serum AMH levels were significantly elevated in PCOS patients compared to controls (4.29 ng/mL vs. 8.97 ng/mL, P < 0.001). The cut-off value of AMH for diagnosing PCOS was 6.105 ng/mL, with an area under the curve (AUC) of 0.832, sensitivity of 0.739, and specificity of 0.768. Diagnostic performance varied across PCOS phenotypes, with the highest AUC observed in Phenotype A (0.865). AMH combined with other sex hormones improved diagnostic efficacy (AUC = 0.923). AMH correlated positively with ovarian volume, LH, and testosterone but negatively with age, fasting insulin, 2-hour postprandial insulin, and HOMA-IR. AMH was an independent risk factor for infertility in PCOS patients (OR = 1.058). CONCLUSIONS: Serum AMH is a valuable diagnostic marker for PCOS in Chinese women of reproductive age, with phenotype-specific diagnostic cut-offs. AMH combined with other sex hormones enhances diagnostic accuracy. Age and BMI influence AMH cut-offs, and higher AMH levels are associated with more severe PCOS phenotypes and increased infertility risk. CLINICAL TRIAL NUMBER: Not applicable.