29 Nov Freezing Eggs vs Freezing Embryos
Freezing eggs vs. freezing embryos are two separate processes – the main difference being in terms of whether the eggs are fertilized before being frozen or after. The idea behind doing it is that by freezing eggs when you’re young, you have a better chance of having healthy eggs leading to viable and healthier babies, the chance of which diminishes as you get older.
The process starts with the female patient being injected with the hormone medication to stimulate the ovaries to produce multiple eggs. When the eggs mature, they are collected from the ovaries and flash frozen with liquid nitrogen. These eggs are then thawed at a later time when pregnancy is desired. They then undergo in vitro fertilization to create an embryo.
Conversely, if it is an embryo freezing process, then the eggs are fertilized to develop embryos, which are grown over several days and then frozen.
The embryos are slightly less delicate and they used to be preferred over freezing eggs, but with the advent of. flash freezing, the survival rates of the freezing eggs and freezing embryos are comparable (90-95%).
One key difference is that you have to choose multiple eggs to freeze in order to attempt fertilizing them later, but that is not required when freezing an already fertilized embryo. For this reason, embryo freezing is not that useful for women who aren’t sure of the partner/sperm donor. It could even create legal issues with your former partner if one of you want to use or discard the previously frozen embryos while the other does not. Moreover, discarding embryos can be disallowed in many faiths, which is not really an issue with freezing unfertilized eggs.
Another factor is that the cost of the egg freezing process is less than that of embryo freezing because the latter m requires in vitro fertilization before freezing. The egg freezing is often twice as expensive as embryo freezing.
Another religious/ethical issue when choosing to freeze embryos is deciding what to do with any surplus embryos that after fertilization. Keeping the embryos frozen is costly and likely impractical. Alternatively, they could be donated to medical research, or for infertile couples instead. If none of these are possible, they may have to be thawed without donating – basically allowed to expire.
These decisions are difficult and require education and counseling of the couples. The couples need to be on the same page and legal contracts and consents need to be meticulously recorded to avoid serious complications in the future. Furthermore, the counseling process should include clinically established statistics regarding survival rates of each method, expected fertilization rates and pregnancy rates, especially individualized to the patient. This helps minimize confusion and allows for well-informed decisions to be made, which is good for all stakeholders involved in the long run.