What happens to leftover embryos from IVF?
Usually, if eggs are being collected from a woman, they collect a bunch at a time by inducing several to be produced by the use of drugs. You don’t want 10 babies to implant all at once in the mother (would be a very complicated birth), but not every fertilized embryo will work every time, so they generally implant 2 or 3, I believe. The process of stimulating egg production takes a while and can be painful, so the extras are frozen in case none of the implanted embryos ‘takes’ and the parents wish to try again. The longer they are frozen, the less likely they are to implant successfully. The final end of the eggs or embryos are up to the donors. Some may be used for research or others may be incinerated (destroyed). For long-term egg and sperm storage, there are usually annual storage fees, so once a couple has the family that they want, the remaining eggs/embryos are destroyed or used for research, as above.
