Embryo freezing, also known as cryopreservation, is a technique employed in assisted reproductive technology where an embryo, usually at the blastocyst stage, is cooled to sub-zero temperatures to halt all biological activity. This process preserves the embryo for future use without any deterioration in quality.

The process begins after an egg has been fertilized by a sperm, creating an embryo. These embryos are then monitored for growth and development. When the embryo reaches the optimal blastocyst stage, typically around day 5 or 6, it is ready for freezing.

Traditionally, the slow-freezing method was used, where the embryo was gradually cooled. However, this technique could sometimes result in the formation of ice crystals, which could potentially damage the embryo.

Vitrification is a cutting-edge freezing technique that avoids the ice crystal problem by cooling the embryos at an ultra-rapid rate. Vitrification turns the embryos into a glass-like state, avoiding ice formation, and thus has significantly improved the survival rate of thawed embryos and increased pregnancy rates.

Vitrification is the most advanced method available for freezing embryos and has been successfully used at Markham Fertility Centre since 2014.   By leveraging this latest technology, we're able to enhance the survival rates of our cryopreserved embryos, thereby providing superior odds of pregnancy in subsequent transfer cycles.

The process of frozen embryo transfer (FET) starts with a discussion with your physician about the plan for embryo transfer and your body's readiness for the process. Your physician will perform some exams and blood work to ensure that your body is optimized for pregnancy.

Maintaining a healthy lifestyle can improve the chances of a successful FET. This includes regular exercise, balanced nutrition, and abstaining from alcohol, caffeine, and smoking. Check out these blog posts on maximizing your physical health prior to frozen embryo transfer.

The process can be emotionally demanding. At Markham Fertility Centre, we encourage patients to use our resources to support their emotional health, such as counseling services or self-care strategies available on our website.

A few days before the transfer, you'll have a final ultrasound. If everything looks good, the clinic will set the transfer date.

Generally speaking, 95% of embryos will survive thawing. However, it is important to note that individual thaw rates may vary and can be influenced by factors such as the age of the eggs when the embryos were created.  If you have more than one embryo cryopreserved, we will thaw them in order of their quality with the highest grade embryos being chosen first. Click here to see a blog post about embryo grading.

At Markham Fertility Centre, our comprehensive services include onsite genetic counseling, providing you with in-depth interpretations of Preimplantation Genetic Testing (PGT) results for each of your embryos. We generally advise against the transfer of aneuploid embryos given their notably low pregnancy rates and high rates of miscarriage. Mosaic embryos, on the other hand, can yield higher live birth rates than previously anticipated. Our team of dedicated genetic counselors, in collaboration with your treating physician, will expertly guide you through this decision-making process. Our goal is to equip you with the knowledge needed to make confident decisions about your fertility journey.

Frozen Embryo Transfers (FET) can be conducted using either a natural or a medicated cycle, and each approach has its own set of advantages. The decision between a natural or medicated FET often depends on individual patient factors, including menstrual cycle regularity, hormone levels, and personal preferences.

1. Natural FET: A natural FET cycle closely follows a woman's natural menstrual cycle. No hormones are administered to manipulate the cycle. Instead, the timing of the embryo transfer is planned to align with natural ovulation, typically determined through regular monitoring of hormone levels and ultrasound. This method is often suitable for women who have regular menstrual cycles and ovulate on their own. Progesterone is started at the time of the embryo transfer to help with implantation.
2. Medicated FET: In a medicated FET cycle, hormones such as estrogen and progesterone are administered to prepare the uterine lining and precisely time the embryo transfer. The use of medications allows for greater control over the timing of the embryo transfer, which can be helpful for those with irregular cycles or other medical conditions.  Medications typically used for a medicated embryo transfer include oral estrogen, transdermal estrogen, or ovulation induction agents like letrozole, or injectable gonadotropins.

At Markham Fertility Centre, our expert team works closely with each patient to determine the best approach based on their unique circumstances. Our goal is to provide a personalized treatment plan that optimizes the chances of a successful pregnancy.

The Ontario Fertility Program covers most of the costs of a an FET for all embryos created from a funded IVF cycle.  You may incur costs for medications, which will be between $300 and $1,000, depending on the protocol selected by your fertility doctor.

If you are using an embryo from an unfunded IVF cycle, expect to be pay between $1,650 (medicated cycle) and $1,850 (unmedicated cycle) plus the cost of medications, which is generally less than $400.

Please refer to the section on Fees for more information.

Yes.  Markham Fertility Centre does accept embryos from outside clinics.  Before transferring embryos to MFC you must meet with one of our physicians to ensure this is the best decision for your specific situation. There is a cost to transferring reproductive material into our lab.   Our Lab will coordinate with the sending lab to make sure all paperwork and information is available before shipping.