When a woman undergoes treatments such as IVF, ICSI in the first step of the treatment woman’s ovaries will be stimulated with hormone injections to produce the eggs. After stimulation, all the eggs that are produced are retrieved by a short surgical procedure and then fertilized with sperm in a laboratory to form embryos.
Not all the embryos formed in this process will have the potential to develop. In most cases, there will also be good embryos which are surplus to those required for embryo transfer for the IVF cycle. The healthy embryos which are suitable for freezing can be frozen. The suitability and quality of an embryo to undergo cryopreservation or freezing will be assessed by culturing the particular embryo and recording observations over the following 5/6 days. If the embryo has developed to the blastocyst stage, generally, it is considered to have the potential to develop and implant. So through this test, the best quality embryos are selected for freezing.
Embryo freezing (cryopreservation) is a method of preserving the viability of embryos be carefully cooling them to very low temperatures (-196oC). This is carried out in the laboratory using specialized freezing equipment and the embryos can then be safely stored in liquid nitrogen for extended periods.
Through an embryo freezing, the ovulation stimulation step can be skipped, if a woman has to undergo multiple IVF cycles. Additionally, this process provides patients with a “back-up” should the initial fresh embryo transfer not result in a pregnancy, at a much lower cost than starting IVF all over again and often with minimal medications. Since the embryos can be frozen and stored for over 10 years, embryo freezing can also help women for their second pregnancy.
While using the frozen embryo, the frozen embryo will be first thawed and then the ability of the embryo to further develop is assessed. On passing the assessment, the embryo is then transferred into the womb for a successful pregnancy.
Egg Freezing, which is also called oocyte cryopreservation is a process in which the woman’s unfertilized eggs are frozen. The eggs are first extracted from the woman after ovulation stimulation, and then frozen to use them in the future. Frozen eggs may be stored for many years without significant deterioration.
This process will help women who must undergo surgery or treatments that may damage the ovaries and further affect the quality and quantity of eggs. This can also help women with ovarian diseases and women who are at risk of ovarian damage. The frozen eggs can also be used to donate them to women who are not able to conceive due to egg related issues, and in women whose quality of eggs are deteriorating.
Like egg freezing, sperm freezing is a process in which the man’s sperms are frozen for future use in IVF or ICSI treatments. These sperms also can be donated with the consent of the donor. Just like embryo freezing and egg freezing, not all sperms can withstand the freezing and thawing process. Only healthy and good quality sperms that can withstand the thawing process are further used for treatments. This sperm preservation is highly helpful for men who are having low sperm count, or persons who are undergoing treatments that can affect the quality or quantity of sperm.