When a couple cannot use the husband’s sperm for fertilization, there is the possibility to use donor sperm. The donor sperm samples are obtained from sperm bank, specially certified for the storage and distribution of such donor samples. All donor are screened for a series of potentially transmitted diseases. In assisted reproduction treatment in which donor sperm is used, the woman has to go through the ovarian stimulation. On the day of oocyte collection the donor sperm will be thawed and used to fertilize the woman’s eggs.