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Freezing embryos, eggs and sperm using liquid nitrogen is referred to as cryopreservation. Liquid nitrogen has a boiling point of -196°C which means that it bubbles ferociously when it contacts anything at room temperature and immediately produces clouds of nitrogen gas. With careful preparation, liquid nitrogen can be used to perfectly preserve embryos and gametes until they are ready for use.

Advancements in embryo freezing has revolutionised IVF

Recent developments in freezing techniques have significantly improved success rates and it has now opened up a new world of IVF. If embryos are frozen correctly they should have almost a 100% survival rate. This means that surplus embryos can be safely frozen and transferred one at a time instead of transferring multiple embryos into the uterus at once. This significantly reduces the risk of having twins to avoid the dangerous complications multiple pregnancies can present for the mother and baby. It also gives women the opportunity to freeze their eggs earlier in life if they are considering postponing their family plans - something that is becoming increasing popular with the next generation of career-driven women.

Men can also take advantage of cryopreservation by freezing their sperm if they want peace of mind that they always have a back-up, perhaps if they are considering a vasectomy. Not only that, but cryopreservation can be essential for men and women undergoing a sex change who may want a family in the future, as well as people who are undergoing fertility-damaging treatments such as chemotherapy.

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Ready to Learn More About Freezing and Thawing?

How are embryos frozen?

Embryos were traditionally frozen using a ‘slow-freezing’ method where the temperature is gradually reduced using a specially designed machine. However, the survival rates of frozen embryos have skyrocketed since...

How are embryos thawed?

When an embryo is ready to be used for transfer it can be thawed out. Although if the embryo has been rapidly frozen using the vitrification procedure, it is locked into...

Embryo freezing - What can go wrong?

The most common problem is that the embryo doesn’t survive the freezing/thawing process. This may be due to...

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