Frozen Embryo Treatment
Assisted conception through IVF is a long process. Unfortunately, there is no guarantee of success and treatment can often involve several attempts at embryo transfer in order to achieve the goal of a live-born baby. For many decades, good quality embryos have been successfully frozen and then thawed to be used to produce healthy babies. IVF treatment stimulates the growth of several eggs and can sometimes produce more embryos than can be used in the first treatment cycle.
The aim of producing a single pregnancy by the transfer of embryos one at a time means that good quality embryos are sometimes remaining after treatment has been completed. These are not wasted but can be stored for future use, either if the fresh embryo does not produce a pregnancy from that cycle, or if there is a wish to have another child some time later.
At Leeds Fertility about 36% of cycles have spare embryos that are of good enough quality to freeze.
If an embryo is of poor quality before it is frozen, it will not have improved after freezing and thawing. Often, poor quality embryos have not survived or are degenerating (dying) upon thaw and we do not transfer these ones.
The quality grade required to attempt freezing is quite high and this helps to maintain good survival of the embryo when it is thawed and also good chance of pregnancy after transfer. The chance of a single embryo surviving the process to reach the transfer stage is currently about 90%.
It is important to bear this in mind, especially if there is only one embryo available in storage. It is disappointing to prepare for transfer only to find on the day itself that no embryo is available for treatment.
For more information, please read our patient information booklet.