When immature bovine oocytes are released from their follicles and are cultured in standard maturation medium, they resume the first meiotic division. The alteration of basic maturation conditions can affect oocyte competence significantly, as reflected by the morula and blastocyst yield after in vitro fertilization. The conditions used from the beginning of maturation up to the blastocyst stag...

the use of donated embryos has offered hope for infertile couples who have no other means to have children. in iran, fertility centers use fertile couples as embryo donors. in this paper, the advantages and disadvantages of this procedure will be discussed. we conclude that embryo-donation should be performed with frozen embryos thus preventing healthy donors from being harmed by fertility drug...