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Cryo-Preservation of Embryos

The cryo-preservation of embryos has changed drastically since the first procedure was done more than 30 years ago. That being said, the intention for embryo storage has remained the same, to increase the chances of a successful pregnancy. At ONE Fertility Kitchener Waterloo, cryo-preservation of embryos is a commonly used method for couples.

Globally, success rates have been increasing with use of frozen embryos than the use of embryos that have not been frozen. It should be noted that research has indicated that there is no increase in the risk of possible birth defects from using embryos that have undergone cryo-preservation in comparison with fresh embryos.

What Is Cryo-Preservation of Embryos?

Cryo-preservation of embryos refers to a technique of saving embryos for use at another time. Frequently called embryo freezing, this process is favourable for women who are undergoing current treatment for a serious health condition, for religious reasons, or for ethical reasons. Younger women may choose to preserve their embryos to be used at a later time in their life.

The procedure begins by removing the eggs from the ovaries to be fertilized, thus creating the embryos. These embryos are then frozen and stored at a low temperature until the woman is ready to use them. Embryos can be stored for up to 10 years, sometimes longer. The frozen embryos are monitored and safeguarded by a qualified laboratory, hospital, or clinic. Once they are ready to be used, the embryos are thawed and implanted into the uterus of the contributing woman or another woman, such as a surrogate.

The Cryo-Preservation of Embryos Procedure at ONE Fertility

As a world-class fertility clinic, ONE Fertility Kitchener Waterloo follows safe and effective cryo-preservation procedures. Our certified fertility specialists and team members take all precautions to ensure your embryos are safely stored and monitored.

We provide a range of fertility assessments and services such as cryo-preservation of sperm and embryos. Continue reading to learn more about our specialized services with embryo cryo-preservation.

Fertility Assessment

Every patient undergoes a thorough fertility assessment when partnering with our clinic. Our fertility specialists meet with both parties involved to determine the need for embryo freezing. Factors that may affect the desired outcome include lifestyle factors, tobacco and drug use, weight issues, excessive alcohol consumption, and any prescribed medication requirements.

Pre-Implant Genetic Testing

At ONE Fertility Kitchener Waterloo, we understand the use of pre-implant genetic testing (PGT) is a controversial method used in some clinics worldwide. We believe and endorse PGT on a selective basis, judging each case with its own merits.

This pre-implantation procedure removes cells from the embryo to test for specific genes within the embryo. A normal embryo will show there is no sign of any disease while an affected embryo has the disease. This form of advanced testing can detect whether an affected embryo is actually affected by the disease or is a carrier of the disease.

Cycle Monitoring at the Clinic

ONE Fertility Kitchener Waterloo performs cycle monitoring (CM). During this process, the woman will undergo blood tests and transvaginal ultrasounds at intervals throughout her cycle. It monitors for the thickness of the uterine lining, size of the eggs, and hormone levels. By tracking this information, the optimal insemination day can be determined.

As one of our specialized services, we maintain a stock of medications to use if necessary to stimulate the egg release. This can happen when the egg becomes mature but the necessary luteinizing hormone levels have yet to spike.

Egg Extraction and Fertilization

Once an ultrasound confirms the presence of eggs, our fertility specialists will begin the egg extraction and fertilization process. The extraction procedure takes very little time with no resulting scars or stitches.

To prepare for cryo-preservation of an embryo, not just the egg, the sperm from the woman’s partner, or donor, will then be used to fertilize the egg. While the embryo is developing, genetic testing can be done before the freezing process begins.


In vitro fertilization (IVF) is one of the specialized methods used at ONE Fertility Kitchener Waterloo. We fertilize the eggs in a special culture medium or by intra-cytoplasmic sperm injection (ICSI) and then place the embryos in incubation for 24 hours. We find upon inspection, nearly 70% of the eggs are fertilized at this time. By day three, the embryos are ready for cryo-preservation.

Freezing Embryos

The chosen embryos are prepared for freezing with the process known as vitrification. The water within the cells of the embryo is replaced with a protective fluid before liquid nitrogen is used to flash freeze the embryo. This allows protection of the cells from formation of ice crystals.

Of the embryos frozen, more than 95% survive thawing. As with regular pregnancies, embryos of women under the age of 35 have a higher chance of being successfully implanted.

Why Choose ONE Fertility

  • Highest Expertise and Level of Care in the Area: Our state-of-the-art facility and highly trained staff offer specialized care, treatment, and counselling.
  • Patient Involvement and Education: The available fertility care and treatment plans are designed specifically for the needs of each patient and their comfort levels.
  • In-House IVF: We provide in-house IVF procedures and monitoring to ensure the highest quality of treatment and care are observed.
  • Range of Services from Beginning to End: Each patient has different needs, which is why from the initial assessment to a successful childbirth, our team of experts are with you each step of the way. We are partners with our patients as they embark on this fertility journey.

ONE Fertility’s Cryopreservation of Embryo Services

Our goal is to provide the best fertility care possible to each and every patient. At ONE Fertility Kitchener Waterloo, we use the most advanced science and evidence-based approach to ensure you receive the highest quality of care along with compassion. Using embryologic science, we can design the best fertility plan for you and your family.

Don’t let the science scare you! The process and procedures involved are safe to you and your embryos. Contact us today for a consultation!

frozen embryos vs frozen eggs


4271 King St East, Suite 200
Kitchener, ON
N2P 2X7

Working Hours

Monday-Friday: 7am-3pm
Saturday-Sunday: 8am-12pm

Contact Us

Phone: 519.650.0011
Fax: 519.650.0033