women contraception men childbearing potential use adequate unwilling pregnant study contraceptive use potential effective reproductive method study methods men agreed contraception methods intrauterine barrier device method use condom potential effective surgically childbearing sterile potential abstain heterosexual activity sterilized study subjects contraception use effective agree potential study childbearing male method female fcbp agree contact sexual vasectomy condom latex successful potential lenalidomide birth control potential effective use study method agree childbearing women bilateral hysterectomy oophorectomy potential consecutive postmenopausal months childbearing tubal undergone