Cryopreservation of oocytes after vitrification.

Recently the majority of studies and research in the field of physiopathology of reproduction have been oriented towards cryopreservation of female eggs. This could resolve the ethical problems connected with the preservation of the embryo and with the gestation of the surplus oocytes collected after cycles of ovarian hyperstimulation. Notwithstanding that extraordinary results have been obtained in the field of cryopreservation of embryos and spermatozoa, the freezing of oocytes involves unfortunately many difficulties in relation, above all, to deep morphostructural and functional modifications which take place due to the low temperatures and to the toxic action of cryoprotective agents. The aim of this work was to test and then verify whether an efficient method of preserving the female egg cells by freezing in order to be able to subsequently use them for in vitro fertilization. The conclusions of this study, even if not highly encouraging, have allowed us to better evaluate the damage caused by low temperatures and at the same time should stimulate us and other researchers in this field to find new methods which will allow us to reach higher aspirations.