It is possible to freeze all existing embryos for replacement in a later cycle. But even if one (or two) embryos are returned in the current cycle, supernumerary embryos of good quality can be frozen. If you do not become pregnant at the first attempt or still want a child later, you can use these stored embryos in a following cycle.
What happens to supernumerary embryos?
In a PGT treatment the decision about what should happen with supernumerary embryos is rather more complex than in a normal IVF/ICSI treatment. Supernumerary embryos are embryos which you cannot have replaced or not immediately, either because there are more than you need or because they are genetically unsuitable. What happens to any supernumerary embryos (freezing or not), is your decision. That is something that you decide in an agreement before the start of your treatment.
- For the healthy embryos you have to decide whether you will allow them to be frozen for use at a subsequent new attempt, or you give them up for scientific research or you have them destroyed.
Giving them up for donation to another prospective parent is not an option after a PGT.
- You can give up sick embryos, embryos for which no diagnosis can be made and embryos of poor morphological quality for scientific research or you can have them destroyed.
- In the case of PGT with HLA typing you have to decide in a separate agreement what you intend to do with embryos that are ‘healthy’ but not HLA-compatible.