fertility preservation in cancer patients: in vivo and in vitro options

oocyte, embryo and ovarian tissue cryopreservation are being increasingly proposed for fertility preservation among cancer patients undergoing therapy to enable them to have babies after the cancer is cured. embryo cryopreservation is not appropriate for single girls without any sperm partner and also because oocyte retrieval is an extended procedure, it is impossible in cases requiring immediate cancer cure. thus ovarian tissue cryopreservation has been suggested for fertility preservation especial in cancer patients. the main goal of ovarian cryopreservation is re-implanting the tissue into the body to restore fertility and the hormonal cycle. different cryopreservation protocols have been examined and established for vitrification of biological samples. we have used cryopin to plunge ovarian tissue into the liquid nitrogen and promising results have been observed. ovarian tissue re-implantation after cancer cure has one problem- the possibility of recurrence of malignancy in the reimplanted tissue is high. xenografting-implantation of the preserved tissue in another species-also has its drawbacks such as molecular signaling from the recipient. in vitro follicle culturing is a safer method to obtain mature oocytes for fertilization and the various studies that have been carried out in this area are reviewed in this paper.