Embryo Banks: Our Institute offers its patients a bank of frozen embryos where surplus embryos from previous cycles are kept for later use. Couples who deposit their embryos here may recover them later, in cases of unsuccessful “fresh” attempts or if they decide to try for a second pregnancy. Our bank also offers frozen embryos for donation, destined for those couples where neither the woman´s oocytes nor the man´s spermatozoids could be used. These embryos mostly come from couples who underwent in vitro fertilization treatment and voluntarily donate their surplus embryos. They may also come from embryos resulting from sperm donors.