Once the embryos have been genetically analysed, it is important to know what will be done with them. Genetically altered embryos will be discarded outright and cannot be transferred.
Healthy embryos, on the other hand, have two possible destinations. On the one hand, some of them can be used for a fresh transfer. If this is not possible or if there are more healthy embryos, then the process would be to vitrify them for transfer in the future, i.e. to make a delayed embryo transfer.