In almost all IVF cycles, the number of embryos which are produced is more than the number which are actually transferred. In these cycles, it may be desirable to cryopreserve (freeze) these “extra” embryos, provided that they are of high enough quality.

Such frozen embryos have a very good chance of success in subsequent treatment cycles, and enable many couples to conceive on multiple occasions from one IVF egg retrieval, since frozen embryo cycles do not require the time or expense of additional fertility medications, egg harvestings, or laboratory procedures.

At CT Fertility, all embryos that are frozen are done so with the vitrification technique, which results in the survival of over 98% of embryos when they are eventually thawed at a later date.

Vitrification is a “quick -freeze” technique that minimizes the formation of ice crystals. This is achieved by using high concentrations of cryoprotectant with rapid freezing to solidify the cell. The frozen embryos are then flash-frozen in a tiny droplet of media on a very thin plastic stick.

Not only do the embryos survive in over 98% of thaws, but implantation rates with frozen embryos ( provided that they were of high grade when they were frozen) are essentially the same as with fresh embryos.