Nives poses an important question that requires good information. The subdermal implant has to be removed by the end of the third year, and can be immediately replaced with a new one. If it is left for a period greater than that indicated, the subdermal implant will have a contraceptive efficacy that is progressively reduced in proportion to the increased amount of time left in, thus increasing the risk of pregnancy. There are not, however, any health risks in general.