An oocyte is the female reproductive cell. Oocytes develop in the ovary, inside the follicles. In the human species, the ovary works in a cyclic way and approximately every 28 days an oocyte matures.
How do oocytes get to the laboratory?
Oocytes get to the laboratory in sterile tubes and kept in growth medium, surrounded by their cumulus cells. The eggs are identified using a microscope, cleaned and kept in culture medium in an incubator at 37ºC.
When do we know how many oocytes have been retrieved?
Minutes after the egg retrieval, all follicular liquids have been analysed and the couple can be informed on the number of collected oocytes.
Do all oocytes obtained in a cycle have the same quality?
The quality of oocytes is a feature unique to each woman, hence not all the oocytes obtained after retrieval are of the same quality.
After retrieval, a heterogeneous group of oocytes is collected; from them, usually 80% of the oocytes are mature, but amongst the remaining 20%, we also find immature oocytes, oocytes with degenerated appearance and atretic oocytes. These last ones are not suitable for In Vitro Fertilisation.