ABSTRACT
Unfortunately, the task is rather demanding. Although the fi rst pregnancy from cryopreserved oocyte was achieved more than 20 years ago (7), advances until recently were very slow. Generally, ineffi ciency and lack of consistency were the two main problems (8). Oocytes are unique cells. Their large size, spherical shape, single cell number, and general fragility explain many of the diffi culties that occur during cryopreservation.
