Embryo freezing allows a second chance of gestation without the need to undergo stimulation or ovarian puncture. Only 10% of embryos fail the process.
The embryos are frozen for the IVF cycle to be effective. During the process, ovulation is stimulated to obtain a sufficient number of oocytes to produce embryos, since not all the oocytes are fertilized and, if there were only 1-3 oocytes, on many occasions there would be no embryo transfer, with the frustration that this entails. If there are embryos left over after a transfer, they are frozen for a second chance or second child.
Once thawed, the embryos are transferred to the uterus. They have an acceptable chance of gestation, almost the same as fresh.
How are the embryos frozen?
Embryos are frozen by vitrification, a cryopreservation technique, with rapid freezing, which does not damage the embryos at all, leaving them intact; with a high content of cryoprotectants.
Advantages of embryo freezing
The great advantage of freezing embryos is that there can be a second opportunity to achieve gestation, with a new transfer, and without the need to undergo stimulation or ovarian puncture again.
Risks of embryo freezing
The only risk of embryo freezing is found in devitrification, when the embryos may not survive. This occurs at only 10%.