What is the effect of cryopreservation on embryo quality

Effect of cryopreservation on embryo quality

Modern reproductive technologies make it possible to cryopreserve (freeze) germ cells and embryos and store them in this state for the required period. But most times, future parents have a legitimate question– how does this process affect the embryo quality?

According to the statistics, the survival rate of embryos after cryopreservation is 97–98%.

How is cryopreservation carried out?

Embryos are frozen in liquid nitrogen at a temperature of -196 degrees. They are first placed in a special solution – a cryoprotectant agent. It prevents the formation of ice crystals, which can damage embryos during thawing.

During cryopreservation, all biological processes in the embryo freeze; therefore, when thawing, it has precisely the same characteristics as at the moment of freezing.

Which embryos are suitable for freezing?

Embryos are cryopreserved at the blastocyst stage (5–6 days of culture) since embryos at an earlier stage may not survive the culture process.

What is the effect of cryopreservation on embryo quality?

It does not affect it at all. No mental or physical developmental abnormalities were detected in babies born from cryopreserved embryos.

How are embryos thawed?

The thawing phase starts 2–4 hours before the transfer. In the meantime, the embryologist instantly removes the straw with the embryos from the cryoprotectant agent, which protects them from damage. This stage is rather tricky but is fine-tuned and verified in our laboratory.

Why do we need cryopreservation?

Thawed embryos are used in the IVF protocol. And this is very convenient for subsequent protocols since the spouses do not need to go through the stages of ovulation stimulation, puncture, sperm donation and fertilisation again.