The process of “freezing” embryos enables people to keep them for later use. Furthermore, unfertilized eggs can be frozen. Following fertilisation and cell division, an embryo develops. After people have therapies to try to get pregnant, embryo freezing frequently takes place. Examples include intracytoplasmic sperm injection (ICSI) and in vitro fertilisation (IVF) (ICSI).
These techniques create more embryos by fertilising eggs with sperm. If you have additional embryos, you could decide to freeze them and use them later.