Fertilization
The embryologist will attempt to fertilize all mature eggs using intracytoplasmic sperm injection, or ICSI, the afternoon following your egg retrieval surgery.
This means that sperm will be injected into each mature egg. Immature eggs cannot have ICSI performed on them.
The immature eggs will be placed in a dish that also contains sperm and nutrition. Immature eggs rarely complete their development in the dish. If an immature egg matures, the sperm in the dish can try to fertilize it.
70% of mature eggs will fertilize on average. For example, if ten ripe eggs are collected, approximately seven will fertilize. If the fertilization is successful, the fertilized egg will develop into an embryo.
If there are a lot of eggs or you don’t want all of them fertilized, some eggs can be frozen before fertilization for later use.