[The male factor. III. Importance, diagnosis and perspectives]

According to the World Health Organization, the male factor is present in 40-50% of infertile couples, therefore the importance of the continuity in multidisciplinary studies related to understand the mechanisms regulation the male reproductive process. Semen analysis is still almost the only instrument for the study of men with disruptions in their fertility. However, the main problem to establish a diagnosis with predictive value for male infertility, is the fact that the morphological and/or functional characteristics of the male gamete that determine its fertilizing capacity are still in the process of validation. Even more, the correlations among semen characteristics and bioactive hormones concentrations in serum, and the individual fertility potential have not been established either. In this context, we discuss here some topics that we considered of great importance in relation to male fertility diagnosis, i.e. the main causes of infertility, the advances in the recognition of the morpho-functional correlation that determines the fertilizing capacity of the male gamete and the criteria that prevail in the laboratory to proper handle and evaluate the semen samples.