According to the guidelines of international medical associations, the semen of one anonymous donor is donated to a maximum of ten families (including the family of the donor himself) and used in medical procedures. As a result of the treatment, more than one child may be born in each family. In the case of disclosed donation, it is assumed that semen is used only for the needs of designated recipients. The donor signs a consent stating that he will not participate in donation programmes at other banks or clinics. The effects of treatment with donor sperm depend on the method used – effectiveness ranges from about 15% with insemination to as much as 60% with IVF.