Egg freezing is often talked about in relation to single women who are hoping to delay parenthood, while trying to minimize the impact of declining egg quantity and quality that waiting might have. On the flip side, embryo freezing is often discussed in terms of assisted reproductive technology (ART) and IVF. And while this is all true, there are more reasons why you might choose egg freezing over embryo freezing (or vice versa). Which is better? It depends on where you are in your journey and your own fertility factors—here, we break it down.
What is egg freezing?
We have a full blog post on egg freezing, so make sure to read that for an in-depth understanding of the process and costs. To sum up: Egg freezing is a method where eggs are retrieved from the ovaries and frozen for later use, essentially setting yourself up as your own egg donor in the future, should you need it due to age-related decline in egg quality or failed fertility treatments due to poor egg quality.
Reasons why you might opt for egg freezing:
You are not ready to have children now but you might want to in the future
You haven’t met the person you want to have kids with yet
You are worried about declining egg quality or quantity
The idea of your biological clock is stressful, and you’d like to relieve some of that pressure
You may be about to undergo procedures or medical treatments that might impact your future fertility (like ovarian surgery or chemotherapy) and hope to preserve the option to have biological children
What is embryo freezing?
Embryo freezing takes egg freezing a step further, fertilizing those retrieved eggs with your partner’s or a donor’s sperm and then freezing the resulting embryos for later use.
Reasons why you might opt for embryo freezing
The reasons why you might opt for embryo freezing are the same as egg freezing—with the added element of having the sperm to fertilize those eggs. If you are committed a sperm source (either a partner or donor) this might be the better option for you.
What are the thaw success rates with egg and embryo freezing?
With recent advancements that have been adopted in almost all fertility clinics, the survival rate of freezing and thawing embryos and eggs is very similar—about 90 to 97 percent for egg thawing and 95 percent for embryo thawing. This means that you can confidently choose the option that makes the most sense for your unique situation, without worrying about one method of freezing and thawing being more effective.
Although survival of the thawed eggs and embryos is critical, it’s not the only variable to consider. The egg is a single cell filled with fluid, where an embryo is made up of hundred of cells and therefore more resilient. Egg freezing and thawing techniques have continued to advance to allow people with eggs the opportunity to store them for the future with the confidence they will be viable when they thaw. But, studies still suggest that even a thawed egg that survived has a slightly lower success rate than a fresh egg. Embryos are more resilient to the impact of the freezing and thawing process when it comes to maintaining quality, meaning that a frozen embryo is just as good as a fresh embryo when it comes to transfer.
Why opt for egg freezing over embryo freezing?
With egg freezing, you allow your future self to have more options when it comes to the question of sperm. If you freeze embryos with a partner and that relationship ends, you only have embryos with that person, instead of frozen eggs that you could use with another partner or sperm donor. If you are concerned about declining sperm quality, you can freeze both eggs and sperm—separately—so that you’re also halting the progression of sperm, without putting all your eggs (literally) in one basket. In the future, if the relationship continues, you can still use the eggs and sperm to create embryos, when you’re ready to grow your family. Egg freezing allows for the possibility that you may want to grow your family with someone else in the future.
Why opt for embryo freezing over egg freezing?
If you’re already in the throes of fertility treatment and are hoping to become pregnant right away, but require IVF to do so, your doctor will recommend freezing any additional embryos that develop from that cycle. This allows you an extra reserve should the current embryo transfer fail. If your transfer is successful, you can choose to keep your other frozen embryos stored if you want to try for another baby in the future.
If you are certain that your partner is the one you’ll be growing your family with in the future, opting for embryo freezing allows you to have embryos on stand-by whenever you decide you’re ready.
Embryo freezing also allows you to know ahead of time how many mature embryos you’ll have available to use. At the time of egg freezing, there is little knowledge about the quality of eggs that are being frozen. What we do know is the age of the eggs and the number retrieved, and so any estimates of success are based on general estimates based on those two factors—not your own personalized characteristics that might be affecting your ability to conceive. When you create embryos, you have more information about those embryos thanks to embryo grading or PGT tests, allowing you decide whether you’d like to retrieve more eggs (at your current age) in order to increase the chances of future success.