When you and your partner go through IVF to grow your family, you typically create a few embryos. Of course, the optimum number your doctor implants depends on your circumstances, but most doctors agree that one embryo at a time gives you the best chance for a successful and healthy outcome.
The option to freeze your remaining embryos allows you to continue to grow your family as you wish, having your doctor implant the remaining embryos over the next few years. But, just how long will your embryos stay viable? Can they remain frozen for two years? Five years? 10? Indefinitely? Here we break down the specifics for you and answer that question.
Why Freeze Embryos?
As we mentioned, a successful IVF cycle can result in multiple healthy embryos, and freezing those embryos that your doctor doesn’t implant at the time preserves them for the future. Patients who opt for preimplantation genetic testing freeze their embryos while awaiting the results of the test. For others, the immediate goal is to freeze their embryos as they undergo medical treatments such as hormone therapy, gender affirmation, cancer treatment, or other medical procedures that may threaten their fertility.
What is Embryo Freezing and How Are Embryos Stored?
Before egg retrieval, your doctor monitors the development of your follicles so they can determine the number of eggs you’ll likely produce. Once your doctor retrieves your eggs for IVF, they go to the lab where an embryologist fertilizes one or more of the eggs with your partner’s sperm, or donor sperm. It takes up to one week (typically 5 days) for the embryo’s development. At that point, the embryologist may test the embryo for genetic abnormalities and viability.
Those embryos deemed viable and healthy that you decide to freeze undergo a process called vitrification. This is a flash freezing method in which the embryologist replaces the water in the cells of the embryo with a protective fluid, and then the embryos undergo freezing using liquid nitrogen that prevents ice crystals from forming. This method poses less of a threat to the viability of the embryos since ice crystals may cause damage.
When your embryos go to the storage facility, typically located in a hospital or commercial embryology lab facility, the facility stores them in a liquid nitrogen tank. Someone monitors your embryos, ensuring their safety and preservation, under highly controlled conditions, 24 hours a day, until you decide you’d like to grow your family.
How Long Can Embryos Be Frozen and Remain Viable?
Embryos may remain frozen and viable indefinitely. Because of vitrification, freezing is virtually instantaneous. To date, the longest time an embryo remained frozen and resulted in a healthy birth was 31 years.
The length of time an embryo remains frozen doesn’t seem to impact viability. There are a few key factors, however, that may affect the frozen embryos and success rates. They are:
- Age: The age of the eggs at the time of the embryos’ creation does impact the overall viability of the embryos. Younger eggs have a higher rate of successful fertilization, embryo development, and implantation. Of course, the age of your eggs affects success in all aspects of reproduction.
- Embryo Quality: The quality of your embryo before freezing is an indicator of successful freezing and viability in the future. That’s why doctors recommend preimplantation genetic testing. When the quality of your embryos is high, the viability and success after thawing and implantation is much greater.
- Freezing Technique: Vitrification leads to much better embryo survival, pregnancy, and live birth rates than other methods.
- Storage of Frozen Embryos: The viability and success rates for embryos stored in consistent and optimal temperatures, and in storage facilities with continual monitoring, are better than for those stored in fluctuating temperatures or subpar equipment. Especially long-term.
Of course, other factors contribute to the success of your pregnancy using frozen embryos. The age of the mother at the time of implantation, the condition of the uterine lining, uterine health, your overall lifestyle, and the skill of your doctor. You may also have a diagnosis of infertility that impacts the overall odds for a successful outcome. You and your doctor will certainly discuss your individual circumstances.
We’re Here to Answer Your Questions
If you’d like to know more about embryo freezing, IVF, or any other fertility treatment, please reach out to LA IVF and schedule a consultation. Our clinics offer the latest in assisted reproductive technology, and our compassionate and knowledgeable staff is waiting to answer any questions you may have. Schedule your consultation with LA IVF today.
