One of the most notable advances in assisted reproduction in recent years has been ultra fast freezing of oocytes –vitrification-, which prevents the formation of ice crystals that used to damage the cell in conventional freezing.
This technique, which became operational in Spain in mid 2007 and was implemented at our center in 2008, has managed to significantly increase survival (96.9%), fertilization (80.6%), optimal quality embryos (64 %) and pregnancy (45%) rates of frozen eggs. The rates are similar to those of non-frozen eggs.