Embryo Freezing and Thawing at WCFC

The first successful pregnancy from frozen embryos happened in 1983 and marked the beginning of a tremendous advance in Fertility Medicine.  The science behind embryo freezing has come a long way since then, making it a standard procedure in most fertility centers.
In a typical IVF cycle, the patient is stimulated to produce a higher number of eggs than they would in a natural cycle.  After the insemination and fertilization of the eggs, couples wait for three to five days to see which embryos will be available for transfer.  The embryos with the best quality are generally chosen for the embryo transfer.  According to ASRM guidelines, West Coast Fertility Centers usually transfers two embryos in patients less than 35 years during any given cycle. Patients with any additional embryos are given the option to freeze them for use at a later time. 

Embryo freezing consists of the following steps:

1. Embryos are exposed to a series of dehydrating cryoprotectant solutions.  The cryoprotectant prepares the embryos by replacing the water in the cells to prevent ice crystal formation.  The cryoprotectant will allow the embryo to remain in a frozen state until it is thawed in the future.
2. Once the embryos are primed with the cryoprotectant they are ready for a journey into our programmable freezer. The programmable freezer constantly controls the temperature as it slowly drops to -180ºC.  Once the embryos have reached this temperature they are transferred to one of our cryo-tanks for storage.  As long as the embryos are maintained in liquid nitrogen (-196ºC) they can remain frozen indefinitely.

The most important part to any embryo freezing protocol is the thawing procedure.  In order for an embryo to thrive after being frozen, it must be thawed with a great deal of expertise.

Embryo thawing consists of the following steps:

1. Just as in the freezing protocol, when embryos are thawed they must be exposed to a series of rehydrating cryoprotectant solutions. This allows for the cryoprotectant to be safely removed from the embryo and be replaced with medium very similar to its original make up. 
2. Once the embryos are carefully thawed they are rinsed in culture media to remove any traces of the thawing media. 
3. The embryos are then placed into a fresh culture media dish and put into one of our incubators where they are kept at a temperature very similar to our body temperature.
4. The embryos are maintained in our incubators until the time of the embryo transfer where they will hopefully implant and achieve a pregnancy

Here at West Coast Fertility Centers we have perfected the art of embryo freezing and thawing. Our enhanced method of freezing and thawing embryos is reflected in the high survival and implantation rates of our frozen embryo transfers.