- Women of childbearing potential must agree to use a reliable and appropriate contraceptive method, which could include a double barrier method (condom plus diaphragm), an intrauterine device or oral contraceptives. Women with ER or PR positive breast cancer, should not, however, use oral contraceptives as a method of contraception. Postmenopausal women must have been amenorrheic for at least 12 months to be considered of non-childbearing potential.