Embryo Cryopreservation (Embryo Freezing) for Fertility Preservation
Embryo cryopreservation, or embryo freezing, is a process in which eggs that have been fertilized with sperm (embryos) are frozen and stored for fertility treatment. It is most commonly used during in vitro fertilization (IVF) or for fertility preservation. The experts at University Hospitals can work with you to determine whether embryo freezing fits in with your overall fertility plan and goals.
Schedule a Fertility Consultation
A consultation can help determine whether embryo cryopreservation may be appropriate based on your medical history and reproductive goals.
To schedule a consultation with a University Hospitals Fertility Center expert, call 216-765-3352 or find a fertility specialist.
Quick Facts
- Embryo cryopreservation involves creating, freezing and storing embryos so that they can be used for in vitro fertilization (IVF).
- Embryo cryopreservation may be performed for use in a current IVF cycle, to preserve fertility before medical treatments, or to preserve fertility for individuals or couples wishing to delay pregnancy.
- Embryos can be stored frozen for many years without affecting quality, and successful pregnancies have been achieved even decades after cryopreservation.
- The reproductive endocrinologists at UH Fertility Center work with individuals and couples to help them understand how embryo cryopreservation can fit into their fertility plan.
What Is Embryo Cryopreservation (Embryo Freezing)?
With embryo cryopreservation, eggs are retrieved from a woman’s ovary and combined with sperm in a laboratory to form embryos. These embryos are frozen and stored at very low temperatures to preserve them for future use. Embryo cryopreservation is not a treatment itself, but rather a preservation method. Frozen embryos can be created during an in vitro fertilization (IVF) cycle, with the intent of transferring them right away, or they can be created to preserve fertility for later pregnancy attempts without repeated egg retrieval procedures.
When Is Embryo Cryopreservation Recommended?
Embryo cryopreservation may be considered in a range of medical and personal situations where preserving future fertility is important. Whether embryo freezing is a suitable choice will depend on individual fertility evaluation. A consultation with a reproductive endocrinologist can help you determine if embryo freezing is an appropriate option.
- During IVF Treatment
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Embryos created during an IVF cycle are kept frozen until it is time to transfer. Usually, only one embryo is transferred into the uterus during the IVF cycle. The remaining embryos will stay frozen and can be used for future IVF attempts.
- Fertility Preservation Before Medical Treatment
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Cancer treatments such as chemotherapy and radiation may cause damage to a patient’s reproductive organs and affect their fertility. Couples may wish to freeze embryos prior to treatment so they can attempt IVF in the future. It may also be considered before other medical treatments such as hormone therapy or gender-affirmation treatment.
- Delayed Family Planning
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Couples may wish to undergo embryo cryopreservation if they are not ready to pursue pregnancy but wish to preserve their fertility for the future. This can be helpful if you are concerned about age-related fertility decline.
What to Expect During the Embryo Cryopreservation Process
Step 1: Ovarian Stimulation and Egg Retrieval
Hormone medications are given to help stimulate egg development. Then the eggs are then retrieved from the ovary through a transvaginal procedure. This procedure is done under sedation and usually takes 20 – 45 minutes.
Step 2: Fertilization
After the eggs are retrieved, they will be fertilized in a laboratory using either sperm from a partner or donor sperm.
Step 3: Embryo Development
Embryos will be monitored for several days as they begin to develop. Usually they grow in the lab for five to seven days before freezing.
Step 4: Freezing (Cryopreservation)
Once the embryos have developed for the appropriate amount of time, they are preserved using vitrification, or rapid freezing. They will then be stored in liquid nitrogen at very cold temperatures (around -196°C).
Step 5: Storage
Frozen embryos are stored in specialized embryology laboratories or long-term storage facilities where they are carefully labeled and monitored to ensure safe storage conditions.
Step 6: Future Use
When they are ready to be used, embryos are thawed and transferred to the uterus during an IVF cycle.
How Long Can Embryos Be Cryopreserved?
Embryos can remain frozen for many years or longer when stored under proper conditions Successful pregnancies have been achieved using embryos that have been stored for more than a decade.
Where Are Embryos Preserved?
Embryos that have been frozen are stored in licensed fertility clinics or specialized cryopreservation facilities. These facilities require advanced laboratory infrastructure, temperature-controlled cryogenic storage and continuous monitoring systems to ensure the safety of frozen embryos or other frozen reproductive materials.
It is not possible to freeze embryos outside of a clinical setting because of the advanced equipment and technologies required. If embryos are kept at a long-term storage facility, the fertility clinic can help coordinate transfer when the embryos are ready to be used.
Embryo Cryopreservation and Fertility Treatment Planning
Embryo cryopreservation is often part of a long-term fertility plan rather than a standalone decision. It is used to support IVF treatment cycles and allows flexibility with the timing of the embryo transfer. It may also reduce the need to repeated egg retrieval procedures for future pregnancy attempts.
Treatment decisions will depend on factors such as embryo quality, the woman’s age at the time of egg retrieval and overall fertility evaluation. Your fertility specialist will discuss these and other factors with you as you determine an individual treatment plan.
Safety Considerations and Limitations
While embryo cryopreservation is overall a safe fertility preservation method, there are some safety considerations and limitations. These include:
- Some embryos may not survive the freezing or thawing process.
- Not all embryos are suitable for freezing: Embryos with genetic or chromosomal abnormalities may not qualify for cryopreservation.
- Pregnancy outcomes vary by individual factors: Successful IVF cycles will depend on a variety of factors, including a woman’s age at the time of egg retrieval/embryo cryopreservation, quality of the embryo, the reproductive health and overall health of both partners, and lifestyle factors.
- Storage costs and long-term storage considerations: Fees for storing embryos in a long-term storage facility can add up when embryos are stored for many years.
- Ethical concerns surrounding unused embryos: Patients must decide what to do with unused embryos once they are done building their family. Options include discarding or donating extra embryos.
Fertility preservation and treatment decisions are very personal. Your fertility team will talk to you about all these considerations to help you understand the risks and decide what is best for your unique situation.
Specialized Care for the LGBTQ+ Community
University Hospitals offers compassionate, collaborative care for the LGBTQ+ community, including fertility and reproductive health services for LGBTQ+ individuals and same-sex couples.
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Frequently Asked Questions
- How long can embryos be cryopreserved?
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If frozen and stored under proper conditions, embryos may be able to remain frozen for many years or longer without affecting their quality. Successful IVF pregnancies have been achieved using embryos frozen more than a decade earlier. Length of storage time alone does not determine the quality of the embryo.
- Where can embryos be frozen and stored?
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Embryos are frozen in a fertility clinic’s laboratory facilities and can be stored before IVF transfer. Embryos not being used right away are often stored in a long-term cryopreservation facility, which can be transported back to a fertility clinic when they are ready to be used.
- Is embryo freezing part of IVF?
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Yes, embryo freezing is usually part of the IVF process. Advanced embryo cryopreservation techniques mean using frozen embryos often has better pregnancy success rates than using fresh embryos. Therefore, most patients opt to undergo frozen embryo transfer, and it is the preferred method for many fertility clinics.
- Can frozen embryos be used years later?
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Yes, if properly stored, cryopreserved embryos can be used for IVF years or decades after they are frozen.
- Does freezing affect embryo quality?
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Embryo quality is not significantly affected when modern cryopreservation techniques such as vitrification are used. These methods prevent damaging the embryo’s delicate cells during the freezing process and ensure that the embryo’s quality is not diminished while in storage. Factors that can affect embryo quality include the mother’s age, the health of the egg and sperm used, and genetic and chromosomal normalcy.
- When should I consider embryo cryopreservation?
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Embryo cryopreservation can be considered when undergoing an IVF cycle or to preserve your future fertility. This may be desired if you are undergoing medical treatment that can affect fertility, such as cancer or hormonal treatments, or if you want to delay having children and are concerned about age-related fertility decline.
- What happens if embryos are not used?
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Embryos that are not used can be put into long-term storage for future IVF cycles. When a couple is done having children, unused embryos can be discarded or donated to other couples or individuals through embryo adoption.
What to Know About Fertility at Every Age
How Young People With Cancer Can Preserve Fertility
The Path to Parenthood: Support for Your Fertility Journey
Related Resources and Next Steps
Explore additional fertility preservation and treatment options offered by the reproductive experts at UH Fertility Center.
Schedule Your Fertility Consultation
A consultation with a fertility specialist can help determine whether embryo cryopreservation may be appropriate part of your fertility treatment plan.
To schedule a consultation with one of our fertility experts, call 216-765-3352.