- NOTE: subjects are considered not of childbearing potential if they are surgically sterile, they have undergone a hysterectomy, bilateral tubal ligation, or bilateral oophorectomy or they are postmenopausal; menopause is the age associated with complete cessation of menstrual cycles, menses, and implies the loss of reproductive potential; by a practical definition, it assumes menopause after 1 year without menses with an appropriate clinical profile at the appropriate age