<qa>  What are the most effective methods for women of childbearing potential?Women of childbearing potential must test negative for pregnancy and agree to use birth control measures that are highly effective. Highly effective methods are defined as those that result in a low failure rate i.e. less that 1 percent per year abstinence when used consistently and correctly, such as implants, injectables, combined oral contraceptives, some intrauterine contraceptive devices IUDs, sexual abstinence, or a vasectomized partner. Likewise, sexually active men must also use appropriate methods of birth control e.g., abstinence, barrier methods with spermicide, or have had surgical sterilization such as vasectomy. 