Embryo freezing (cryopreservation)
Embryo freezing (cryopreservation) is a well-established form of assisted reproduction. When there are excess embryos after an in vitro fertilization (IVF), they can be cryopreserved for later transfer. Embryos can be frozen at any stage. They are mixed with special fluid to protect from damage during the freezing process. This procedure enables multiple embryo transfers from a single egg collection and improves the chances of your success.
As to the preparation process, uterus is usually prepared with hormones and monitored for its readiness to accept the embryo. Following ovulation, Cryopreserved embryos are thawed and transferred back into the uterus. Thawing of embryos involves removing the embryos from the liquid nitrogen and thawing at room temperature and mixing it in a special culture media. The mixture is then kept in the incubator ready for transfer. Pregnancy testing usually occurs 8-10 days after the embryo transfer.
Embryo freezing has significant benefits as it maximizes the potential for conception for IVF. The advantage of frozen embryos is that they can be replaced in future IVF cycles without the patient having to repeat drug treatment and egg retrieval.
This procedure is recommended for women who are at a high risk of developing severe ovarian hyperstimulation syndrome during IVF procedure and who have cervical stenosis. It is also used before cancer chemotherapy or radiology.
Success rates are high if high quality embryos(s) are transferred. Please, note that not all embryos survive the freezing and thawing process. The favorable outcome usually depends on the woman’s age, the number and quality of embryos transferred and the method used for freezing embryos.
There are some ethical and moral issues related to human embryo freezing that is widely debated all around the world. Freezing embryos is an important decision and should be made with informed consent.