- Females of childbearing potential should either be surgically sterile (hysterectomy or tubal ligation), or should use a highly effective medically accepted contraceptive regimen. A highly effective method of birth control is defined as those which result in a lower failure rate (i.e., less than 1% per year) when used consistently and correctly such as implants, injectables, combined oral contraceptives, some intrauterine devices (IUDs), sexual abstinence or vasectomised partner.