AMH and breast cancer: According to the BC, POR is characterized by the presence of at least two of the following criteria: (i) a prior insufficient response, defined as the retrieval of ≤3 oocytes during standard COS; (ii) abnormal ovarian reserve, indicated by an antral follicle count (AFC) of <5–7 follicles and/or anti-Müllerian hormone (AMH) levels of <1.1 ng/mL; or (iii) maternal age exceeding 40 years.