Gametes and Embryos Cryopreservation in Oncologic Patients

Cryopreservation is a technique in which cells and tissues can be preserved at low temperature (-196 °C in liquid nitrogen). The advantage of this procedure is possibly the structural and functional preservation of gametes, embryos and male and female tissue, through the use of specific reagents, also known as cryoprotectors. In addition, cryopreservation is strongly recommended in the case of severe pathologies; for instance, oncologic patients who undergo chemo or radiotherapy treatments could be predisposed to infertility. In the past, cryopreservation was obtained using slow-freezing processes, but nowadays, thanks to several studies in this field, other approaches are taken into account, such as vitrification. Vitrification is used for gametes, avoiding several technical problems, but it’s not used for embryos and ovarian tissues, yet. As for the concerns regarding ovarian tissue, there is already evidence of successful implementation after thawing previous frozen ovarian tissue. However, this technique needs to be more deeply investigated to understand whether vitrification or slow freezing is the best approach. The advantage of freezing ovarian tissue in an oncologic patient, for example, is that no ovarian hyperstimulation is required before the tissue is harvested. Differently, for male oncologic patients, it’s enough to obtain the seminal liquid, except for pediatric patients in whom the cryopreservation of testicular tissue is recommended. 

Keywords: Cryopotector, Embryos, Fertility, Oocytes, Ovarian tissue, PMA preservation, Spermatozoa, Tumor, Vitrification.