Egg, embryo and sperm freezing

What is freezing?

With freezing (cryopreservation), human eggs, embryos, blastocysts, sperm, and ovarian and testicular tissue are stored in liquid nitrogen at −196 °C. They can be kept for a long time, even for years, in a kind of “sleep” in which all cell functions stop. After thawing, the cells regain all the normal functions they had before.

Freezing eggs, embryos and blas­to­cysts by vitri­fi­ca­tion

With this newer method, eggs and blastocysts can now be frozen with high success rates. With the older slow-freezing method, pregnancy rates were very low. Vitrification prevents ice from forming inside the cells. Freezing is very fast, and at our clinic clinical pregnancy rates after frozen embryo transfer reach up to 61%.

Greece’s first babies after vitrification were born at Fertility Clinic Thessaloniki.

Fertility preser­va­tion for older women and before chemotherapy or radio­therapy

• Women of more advanced reproductive age, or who are approaching the menopause, can store their unfertilised eggs for years by vitrification in liquid nitrogen at −196 °C and use them later.
• The same applies to patients who are about to have chemotherapy or radiotherapy, which can damage the ovaries and testes.

For women, we can freeze:

• Unfertilised eggs
• Fertilised eggs
• Ovarian tissue

For men:

• Sperm
• Sperm taken from testicular tissue