After brief maturation in the laboratory (2-4 hours), the embryologist chooses the mature oocytes and places them, individually, with the prepared sperm in a culture dish in special culture media, allowing them to undergo the fertilization process. Oocytes which are immature, are kept for further maturation before fertilization.
The oocytes will be checked after 12- 18 hours incubation to check for fertilization.
Fertilized oocytes (embryos), are observed and evaluated for the next few days, and the couple is informed accordingly. The best quality embryos are chosen and embryo-transfer is scheduled, 48- 72 hours after oocyte retrieval.