To ensure that you have a good chance of getting pregnant it is important that the best quality embryos are selected for transfer, especially when only 1 embryo is transferred at a time.
To ensure success if the first transfer fails, it is also important that the embryos most likely to survive freezing and thawing are selected for storage.
Embryologists therefore play an important part in the success of your treatment – they decide which embryos are transferred and which are frozen and stored.
Embryos can be transferred back to your womb at different times of their development. This may help to decide which embryo has the best chance of carrying on developing to establish a pregnancy.
After an embryo transfer, an embryologist carefully assesses the quality of any remaining embryos to select which embryos are suitable for freezing and storage.
Good quality embryos can be frozen and stored to be used in follow-on treatment if the first transfer using the fresh embryo is unsuccessful.
Higher quality embryos have a better chance of surviving the freezing and thawing process.
Clinical Embryologists are state-registered scientists who have:
and have either:
Embryologists use their training and experience to assess embryos and select those most likely to implant in the womb and continue to develop.
They do this by applying a system of grading, using criteria for early stage embryos such as:
Different grading schemes are used for embryos when they reach the blastocyst stage (around day 5 of their development).
After the grading system has been applied to the embryos, any suitable ones are selected for transfer and storage.
Grading systems vary slightly, depending on your clinic, but they all produce similar results.
Recent improvements in technology have lead to the development of a new type of system called 'time-lapse' which allows the embryos to be constantly monitored within an incubator.