Lastly, a pregnancy test will be conducted on the urine sample if the child is female and has reached puberty. The child should not be in this study if she is pregnant or a nursing mother. A positive urine pregnancy test would cause the child to be removed from the study. If the child is sexually active, she must be using an effective method of birth control during her participation in this study. Acceptable methods of birth control are oral contraceptive medications (the administration of which must be parentally supervised), IUD, depot medication and tubal ligation.