[Criteria for evaluating the quality of ovocytes and their aptitude for IVF].

Oocyte quality comprises the cell's normality and its maturity. It can be estimated in a nondestructive manner, using the following parameters: Analysis of the follicular fluid. Follicular hormone status changes little during oocyte maturation, and its analysis is not conclusive except in rare cases where the steroid hormone levels deviate considerably. The quantification of certain proteins in the follicular fluid (alpha 1-antitrypsin, fibrinogen, IgG) is a better criterion. Characteristics of the perioocyte cells. The mucous condition of the cumulus oophorus is usually correlated with maturity, and thus with the capacity for fertilization, but this correlation no longer exists if certain ovary stimulation treatments are used. The abundance of vacuoles in the cells of the cumulus is associated with atresia, while an increased lipid content indicates post-maturity. When the cycle has been stimulated with hormonal treatments, several follicles can deliver fertilizable oocytes even though the hormone characteristics of the follicles, as well as the appearance of the perioocyte cells, differ from the conditions seen in the spontaneous cycle. Follicles of sufficient size (3 to 5 ml, depending on the treatment) contain the oocytes with the greatest capacity for development: however, the rank of a follicle (hierarchical position) in the ovarian cohort does not influence the fertilizability of the oocyte it contains.