AMH and polycystic ovary syndrome: The key take home points include the following: (1) serum AMH declines in a non-linear fashion with cross sectional age; (2) among those with normal serum androgens and regular menstrual cycles, 5-year reference ranges for serum AMH were established, and the upper 90th and 95th percentiles were 31.8 pmol/L and 50.41 pmol/L, respectively; (3) AMH was not associated with BMI, insulin resistance, or smoking, (4) using two or more of three features consistent with PCOS (FAI > 8.5, OM/AM, and/or AMH at the 90th and 95th percentiles), PCOS was present in 5.1% or 3.4%, respectively.