Why should you consider freezing your embryos?

After an IVF cycle there may be leftover embryos. You can choose to freeze these embryos for use in the future rather than going through another cycle of ovarian stimulation and egg collection.

When you are going through IVF treatment, if the conditions are not suitable for transfer, we may have to cancel the process after egg collection. For example if your endometrium is not fully developed, or if you have fluid in your fallopian tubes, or if you over respond to your medication developing ovarian hyperstimulation syndrome then we cannot move forward with the embryo transfer.

If you are planning to have the blastocyst(s) genetically tested. Embryos can be frozen to preserve fertility which makes it possible to get pregnant at a later time.

When are your embryos frozen?

Only good quality embryos are chosen for freezing because they will have the best chance of surviving the thawing process and successful implantation.

There are different stages when the embryos can be frozen:

  • Embryos selected on day 2 or 3 of their development are cleavage stage embryos.
  • Embryos selected on day 5 or 6 of their development are blastocyst stage embryos.

What is the embryo freezing process?

To draw the water out from the embryos, they are put in a special solution containing cryoprotectants which also protects the cells from damages by ice crystals that are formed during freezing.

Slow freezing and fast freezing(or vitrification) are the two processes of cryopreservation used in IVF labs. Vitrification is the more popular process because the water molecules don’t have the time to form ice crystals when frozen rapidly. They solidify into a glass like structure instead.

After freezing the embryos are stored in liquid nitrogen tanks till you decide to use them.

lab testing

Are the embryos damaged by freezing/thawing?

Most embryos survive the freezing/ thawing process but some may not. It is also possible that the surviving embryos may lose one or two cells or develop fragments. Our expert embryologist or consultant will tell you if the embryo is suitable to be transferred or not. Generally 95% of blastocyst stage embryos and 80-85% of cleavage stage embryos survive the thawing process.

What is the duration that the embryos can be stored for?

The length of time of freezing does not affect the embryos. Different countries have different standard storage times of embryos. Our expert fertility team will advise you about this.