For nearly 40 years, embryo storage has helped millions of people fulfill their dreams of becoming parents. Whether you are a single person, a childless couple, or a family yearning to have more children, embryo storage may be the golden lining you are searching for.
What Is Embryo Storage?
Embryo storage is the process of freezing embryos to be used at a later date. Commonly known as cryopreservation of embryos, this action entails removal of most of the cells’ water and replacing it with a cryoprotectant to properly retain the living cells and tissues. This will suspend the growth of the embryo until a time at which it will be transferred into a uterus.
How Do I Prepare for the Embryo Storage Process?
Before initiating this process, it is crucial to plan carefully and get all the necessary information from your fertility clinic. Meeting with your clinic can help you understand the benefits and limitations of embryo storage and clarify any doubts you may have. Additionally, it is essential to understand the associated costs involved in the procedure, from fees associated with freezing to the ongoing storage cost. For peace of mind, make sure to have open communication with your provider and ask any questions you may have to ensure that you feel comfortable and informed throughout the entire procedure.
Who Can Benefit from Embryo Storage?
Embryo storage is a valuable option for many different people. Whether you’re undergoing IVF and want to keep embryos for future use, are worried about medical conditions affecting your fertility, or simply looking to delay having children, embryo storage can be of great benefit to you. It’s also a helpful tool for members of the LGBTQ+ community who are looking to build their families, as it offers the opportunity to plan ahead and ensure that they have the best chance of having biological children when they’re ready.
What Is the Process of Cryopreservation?
I. Patient Evaluation and Selection
First, patients will undergo a fertility assessment to determine if embryo freezing is the best option. A fertility specialist will review both parties’ medical histories, sexual histories, past conception failures and successes, and lifestyle choices. The assessment will also consider factors such as weight, medication use, tobacco and recreational drug use, and overall physical, mental, and emotional health.
II. Cycle Monitoring and Medication
Cycle Monitoring (CM) is performed to track hormone levels, the size of the follicles, and the thickness of the uterine lining. Monitoring allows the fertility specialist to determine the best day for insemination. The female will undergo various blood tests and transvaginal ultrasounds through her menstrual cycle and medications may be necessary to stimulate the release of the egg.
III. Egg Retrieval and Fertilization
Classified as a minimally invasive procedure, the egg retrieval is performed quickly and effectively with ultrasound guidance. A sperm sample is collected (if using a partner’s sperm) and then combined with the eggs for fertilization through either in vitro fertilization (IVF) or intra-cytoplasmic sperm injection (ICSI).
IV. Embryo Development
After the eggs are fertilized, the embryos are closely monitored in a culture medium for five to six days. Embryo development involves four stages: Zygote D1, Embryo D2-3, Morula D4, and Blastocyst D5-6. During this process, about 80% of eggs will fertilize on day 1, and of those, about 30% to 50% will make it to the blastocyst stage (day 5 or 6).
V. Preimplantation Genetic Testing (PGT)
After the embryos have made it to day 5, patients have the option of doing Pre-Implantation Genetic Testing (PGT). PGT screens for potential diseases and disorders that could be passed on to the embryo by one or both of the partners. It also determines whether the embryo has the normal number of chromosomes (euploid) or if it has an abnormal number (aneuploid or mosaic). Healthy embryos have a higher success rate.
VI. Cryopreservation using Vitrification
During the vitrification process, the water within the cells of the embryo is replaced with a cryoprotectant agent (CPA) to prevent ice crystals from forming during the freezing process. Liquid nitrogen is used to rapidly freeze embryos. This flash freezing does not harm the embryo as more than 95% of frozen embryos survive the thawing process.
How Long Can I Keep My Embryos in Storage?
A healthy embryo can be preserved in the freezing stage indefinitely. While most people choose to use stored embryos within 10 years, the longest recorded (successfully transplanted) embryo is 27 years.
What Is the Difference Between Egg Freezing and Embryo Freezing?
Egg freezing, or oocyte cryopreservation, is a process wherein the eggs are retrieved from the ovaries, frozen, and placed in storage for future use. When needed, the eggs can be safely and effectively thawed and the surviving eggs are injected with sperm for lab fertilization.
Embryo freezing, also known as embryo cryopreservation, involves collecting and fertilizing eggs through in vitro fertilization (IVF), then freezing and storing the resulting embryos in a specialized facility.
Frozen eggs and embryos are stored in a canister submerged in liquid nitrogen to maintain sub-zero temperature of -196°C. Eggs and embryos can be frozen indefinitely. Both processes are done for various fertility treatments, including IVF.
How Long Does the Process of Freezing Embryos Take?
I. Preparation (4-6 weeks)
Before an embryo can be created and subsequently frozen, the ovaries need to be stimulated and eggs need to be retrieved, which could take 2-3 weeks. Since only one mature egg is typically released during ovulation, the woman may undergo hormone injection treatment for up to 10 days to increase the chance of having multiple eggs develop. After the eggs are retrieved and fertilized, it takes around 3-6 days for the embryos to develop.
II: Freezing & Storage (1-2 days)
Viable embryos are selected and prepared for the cryopreservation process within 1 day. Vitrification is performed the same day or may be done the next day to switch the water in the cells with the CPA. The frozen embryos can be stored for years.
What Are the Payments for Storing My Embryos?
The payments may be partially covered by some medical insurance programs. Each individual accredited fertility clinic has its own payment plan. Costs associated with storing an embryo cover hormone treatment, egg harvesting, fertility, embryo culture, storage and freezing, and implantation.
Is Embryo Freezing Covered Under Funding Programs?
While the provincial government began the Ontario Fertility Program in 2015 to help eligible candidates, embryo freezing is not covered.
What Is Vitrification?
The freezing of an embryo may be done with the vitrification process. Unlike traditional methods of slow freezing of the cells, this procedure sees a rapid or flash freeze to prevent any ice crystals from forming. Vitrification is done to increase the chances of a viable embryo by lowering the risk of damage due to the freezing method.
How Many Eggs Are Removed from the Ovaries at a Time?
As individual as the fertility clinic itself, the number of eggs retrieved will be dependent on a number of factors. The eggs that are deemed viable (matured) will be removed from the ovaries, up to 15 per cycle.
How Is the Viability of an Embryo Decided?
With only mature or good-quality embryos to be used in the cryopreservation process, a grading system is done to determine which embryos are to be stored. They may be frozen at an early stage of being a single cell, during the two to eight cell stage, or in the later blastocyst stage.
How Many Embryos Can Survive Cryopreservation?
In most cases, more than 95% of frozen embryos survive both the freezing and the thawing processes. The embryos retrieved from a woman under the age of 35 years have a better chance of surviving the cryopreservation process.
Can Freezing Damage the Embryos?
In short, yes and no. While the survival number is high, there are some embryos that do not endure the freezing and/or thawing process. Furthermore, some of the surviving embryos may lose cells but continue to develop.
Are Frozen Embryo Transfers Successful?
Yes, according to the international Centre for Commercialization of Regenerative Medicine, recent numbers from a 2022 study show more than 68% frozen embryo transfers resulted in a successful birth. The chance of a live birth slowly declines in women over the age of 40.
What Is Done in Case I No Longer Wish to Store My Embryos?
For many medical and personal reasons, a person may decide not to use the frozen embryos and want to discontinue with embryo storage. In these cases, the options depend largely on the jurisdiction of which the fertility clinic is regulated. For some, the options include donation to another person or for research purposes and training. The option to dispose of the embryos as medical waste is also available.
How Are Frozen Embryos Discarded?
As with any choice to stop future use of a stored embryo, all parties involved must agree and sign a consent form, which is legally binding. The related embryos are retrieved from storage and naturally left to thaw to room temperature without any medical interference. The embryos are then discarded in the clinic’s medical waste.
Contact ONE Fertility Kitchener Waterloo for Embryo Cryopreservation
ONE Fertility Kitchener Waterloo offers embryo cryopreservation as part of our fertility services. As with our evidence-based approach with our IVF (in vitro fertilization) and IUI (intrauterine insemination) services, we provide an individual plan for your embryology needs. Speak to our consultation specialists today to discuss how we can help you on your fertility journey or contact us to book a consultation with one of our esteemed fertility specialists.
