Embryo freezing and egg freezing are both forms of assisted conception treatments used to store embryos or eggs for later use. Both embryo and egg cryopreservation consist of freezing, thawing fertilization via intracytoplasmic sperm injection (ICSI), and implantation into the uterus of the mother. Both of these methods have provided beneficial results to couples wanting to conceive, but the success rates of these procedures substantially differ.
Embryo freezing, also called embryo cryopreservation, is the process of freezing and storing an embryo for later use. An embryo consists of an egg and sperm that is already joined, containing genetic material from the male and female parents. Embryos are more stable than the fragile eggs, leaving them less prone to damage during the freezing and thawing processes. A benefit of embryo freezing, compared to egg freezing, is that a successful embryo implantation is twice as likely compared to egg implantation.
Egg freezing, or oocyte cryopreservation, consists of freezing an egg (for future use) and then fertilizing it with sperm after it is thawed for implantation. An egg/oocyte contains genetic material of the female it was retrieved from. Since eggs are extremely delicate, potential complications are a likely occurrence during the processes of freezing, thawing and fertilization. Oocyte cryopreservation procedures have shown lower chances of success compared to embryo freezing. Doctors and scientists have expressed some concern over the extent of chromosomal damage that may occur to the egg before implantation, but results from research and studies have shown that once the eggs were transplanted into the mother, the babies were born healthy with no malformations.
Reasons to Freeze
There are many different reasons that single individuals, along with couples, decide to preserve their eggs or embryos. Since fertility tends to decrease with age, some women/couples undergo the procedure to beat the biological clock of the human body. Both radiation and chemotherapy (used to eliminate cancer) have destructive effects on fertility, making it almost impossible for a woman to conceive after the treatments are completed. Before undergoing chemotherapy and/or radiation therapy, women often seek to undergo a cryopreservation procedure in order to increase the likelihood of having their own biological children.
Another primary reason for cryopreservation procedures is that many women/couples do not feel that they are ready to take on the responsibility of raising children. Some couples/individuals have educational goals or life achievements that they feel are necessary to accomplish before conceiving, while some couples simply lack confidence in the lasting of their relationship. No matter what the reason may be, embryo and egg cryopreservation provide a significantly higher chance of conception for women/couples when they are ready to commit to the immense responsibility of having children.
Health risks and side effects are not extremely common with embryo and oocyte cryopreservation. Some patients have experienced symptoms such as vomiting, nausea, shortness of breath, and/or abdominal pain and swelling due to fluid build-up in the abdominal cavity. While these symptoms do affect some individuals, most patients go through the entire procedural period without any health problems or illnesses.