[Comparative study of the morpho-functional features of the sperm of fertile and infertile men and their relation to fertilizing ability].

The recent advances in assisted reproduction procedures have helped to the better understanding of the female reproductive physiology and pathology, however, male infertility remains as a poor explained medical problem, nevertheless it occurs in almost 50% of infertile couples. Oligoasthenozoospermia is one of the more common causes of male infertility, therefore we measured in 10 patients with this diagnosis and in 10 fertile euspermic men, besides the parameters included in the standard semen analysis, the quantitative motility (photography method), capacitation-acrosome reaction and the sperm ability to fertilize zona-free hamster oocytes, with the aim to correlate the morphofunctional characteristics of the male gametes with their fertilizing capacity. The results showed significant differences in every parameter studied, including the correlation analysis. In relation with the in vitro induction of the acrosome reaction in both groups, we found significant correlations of the sperm fertilizing ability and the progressive sperm motility with this parameter (fertile group: RS = 0.834, P less than 0.005 & RS = 0.612, P less than 0.05; infertile group: RS = 0.986, P less than 0.001 & RS = 0.536, P less than 0.05 respectively), nevertheless the sperm rate which completed this process was low in relation to the total sperm population even in the fertile men (9.4 +/- 2.0% & 4.4 +/- 2.5% acrosome reacted cells after 18 h of incubation, in the fertile and infertile males respectively). The results also showed the presence of fully capacitated spermatozoa in both groups, since they penetrated the zona-free hamster eggs and decondensed their chromatin (73.9 +/- 13.4% & 10.4 +/- 7.7% penetrated eggs in the euspermic and oligoasthenozoospermic individuals respectively), however, the spermatozoa from the oligoasthenozoospermic men showed low polyspermy indexes too (0.1 penetrated spermatozoa/inseminated oocyte). In this last group we found, in addition, that the mean sperm velocity and the abnormal sperm morphology rate showed significant correlations with the fertilizing ability of the male gametes too (RS = 0.986, P less than 0.005 & RS = -0.942, P less than 0.005. respectively). These data allow us to suggest that before an infertile man is involved in any assisted reproduction program, the presence of possible morphofunctional alterations in the spermatozoa be analyzed, with the aim to be able to make a better prognosis about the success with these patients.