Oocyte Freezing

Cryopreservation of oocytes can be an alternative to embryo freezing and can be offered to a woman without a partner. However, human mature oocytes have proven to be much more susceptible to cryoinjury than embryos. Clinically, there are three options for storing oocytes at low temperatures, including cryopreservation: 1) at the MII (Matue) stage, 2) at the GV stage, and 3) as immature follicular oocytes within ovarian tissue. Oocyte freezing technology at the MII stage has improved in the last 4-5 years, which resulted in higher pregnancy rates. To date, over 500 babies around the world have been born from frozen-thawed mature oocytes.