The eggs are not extracted and frozen individually but rather in groups. Usually with each menstrual cycle, our body uses between 20 and 50 eggs for ovulation, depending on the woman. Of these, usually only one egg ovulates naturally, which is the one which reaches the best maturity. In order to undergo vitrification, hormone stimulation is performed to try to recover all these eggs and to try to collect around 15 or 20 to freeze.