Embryo Freezing: Is It The Right Choice For You?
As you age, your fertility slowly declines. By freezing eggs or embryos when you’re young (usually under the age of 40), you can preserve your eggs’ health and, through in vitro fertilization (IVF), become pregnant at a later age.
Egg and embryo freezing is also a good idea if you’ll be undergoing treatment, such as chemotherapy, that may reduce your fertility or could potentially harm the health of your eggs.
Is a Frozen Embryo a Fertilized Egg?
Yes, a frozen embryo is a fertilized egg. Both egg and embryo freezing procedures involve the retrieval of your eggs from your uterus. The difference is whether you are freezing eggs unfertilized or freezing fertilized eggs, which are known as embryos.
Freezing Fertilized Eggs Vs Unfertilized Eggs
Embryo freezing (fertilized egg freezing) is often done after an in vitro fertilization (IVF) treatment when there are additional embryos that you want to preserve. However, even if you aren’t ready for IVF, you may choose to freeze embryos rather than eggs for future IVF treatments.
The biggest consideration for embryo freezing is who will provide the sperm to fertilize your eggs. If you do not currently have a partner or do not want to use an anonymous sperm donor, you may choose egg freezing rather than embryo freezing.
Even if you do have a partner, be aware that if you and your partner separate, you may no longer have permission to use the preserved embryos. In some cases, to keep your options open, you may choose to freeze both embryos and eggs.
One of the benefits of IVF embryo freezing, however, is that you will know in advance how many embryos you have. Not all fertilized eggs will turn into embryos, so by freezing embryos versus eggs, you are reducing the risk of not preserving enough eggs for later IVF treatments.
The Embryo Preservation Process
Similar to egg freezing, embryo preservation starts with retrieving mature eggs from your womb. However, rather than freezing the eggs right away, the eggs are fertilized after retrieval by mixing each egg with sperm in a petri dish or by injecting a single sperm into the egg.
The eggs then mature into embryos over approximately five days. Once the eggs mature into embryos, they can be either transferred to the uterus or frozen via the IVF embryo freezing process. Embryos frozen by vitrification, which involves freezing the embryo rapidly at sub-zero temperatures, have a higher chance of surviving the de-thaw process than other methods of embryo freezing.
How Long Can You Keep A Frozen Embryo?
As long as the embryos are properly stored, your embryos should remain healthy and ready for use indefinitely. Studies have shown no significant effect of storage time on embryo survival after thawing for frozen embryos.
Also, the duration of storage had no significant impact on pregnancy, miscarriage, implantation, or live birth rates.
Are Frozen Embryo Transfers More Successful?
Typically, we can successfully thaw 90 percent of embryos. In fact, frozen embryos have a slightly higher success rate than fresh embryos when it comes to achieving pregnancy.
However, depending on your circumstances, a fresh embryo transfer may be better than the additional cost and time of a frozen embryo transfer, so it's important to consult with a fertility preservation specialist about what is best for your circumstances.
The Frozen Embryo Transfer Process
Once you are ready to become pregnant, you will begin the frozen embryo transfer process. This process starts with an ultrasound of your uterus to make sure that it is in good health. You may also need to take medication to optimize the lining fo your uterus for implantation.
Frozen embryo transfer cycles use less medication, and the process is typically far easier and less stressful than undergoing a fresh IVF egg transfer.
Once your doctor has determined that you are ready for the frozen embryo transfer process, your doctor will transfer the embryo(s) into your uterus. Typically, we recommend transferring only one to two embryos to reduce the risk of a multiple pregnancy.
The embryo transfer process is similar to a pap smear. Your doctor will insert a speculum into your vagina to keep the vaginal walls open. Using ultrasound for accuracy, your doctor will then pass a tube through the cervix and into the womb. From there, the embryos are passed through the tube and into the uterus.
The process is usually pain-free and we rarely have to give any sedatives. Some women may experience cramping after frozen embryo transfer or feel discomfort as a result of having the speculum inserted.
If you want to learn more about embryo freezing, schedule an appointment with one of our specialists.