Embryo Freezing

Once an egg is fertilized it is possible to freeze the embryo (fertilized egg) for later use. If more embryos are created in an IVF cycle than are to be transferred, embryo freezing may be an option. The main benefit of embryo freezing is that it allows the couple to have another embryo transfer procedure without having to go through the complete IVF cycle again. If the initial IVF cycle was unsuccessful, then the frozen embryos can be used to attempt pregnancy again. Alternatively, if the initial IVF cycle was successful then the couple may return several years later and use the frozen embryos to try and have another child. Transfer of frozen embryos is less expensive and not as complicated as the initial IVF cycle.

The pregnancy rates with frozen embryos are usually lower than that of fresh (non-frozen) embryos. Not all embryos that are frozen will survive the thawing procedure. It is our policy to only freeze those embryos that we feel are of good quality and are likely to survive the freezing and thawing process. Therefore, not all IVF patients will have embryos available for freezing. Once a pregnancy is established with frozen/thawed embryos, the outcome appears to be no different than that of fresh embryo transfers.

It is not known how long embryos can be frozen and still produce a viable pregnancy when thawed. Most patients will use their frozen embryos within a few years of when they were created. We do not have a strict time limit on the duration we will keep embryos frozen in our laboratory. As long as the couple maintains contact with our clinic, the embryos will remain frozen in our facility. There is a yearly charge for storage of the frozen embryos. Not all IVF couples want to have embryos frozen. If an IVF couple does not want to freeze their embryos, we can modify the IVF cycle such that excess embryos are not created.