[Epidemiological studies of the male reproductive potential: sperm quality as a marker of reproductive health].

Currently, the global demographic crisis in industrialized countries, including Russia, is accompanied by a decrease in the reproductive potential of human populations. In different regions of the world, a decrease in male fertility has been observed that expressing in poor semen quality, increasing in the proportion of male factor in infertile couples and the growth of congenital anomalies of the male reproductive system, resulting to infertility. The observed negative trends in a range of male reproductive problems highlighted the global problem of maintaining mens health, as well as raised the question of the causes of this phenomenon. Taking into account the increasing risks associated with reproduction of humanity, epidemiological studies of male fertility have been started in various countries of the world. The purpose of this review is to analyse epidemiological studies of male fertility, regional and ethnic differences in biological indicators of male fertility. The review provides information on regional and ethnic differences in male fertility in Western Europe, the United States, China, Japan and other countries. Based on our review of epidemiological data we can conclude that the region of residence and ethnicity are important determinants of the male reproductive potential, which can have a significant impact on its variability. Traditional methods of population studies of male fertility are considered, based on which time trends, regional and ethnic differences in the male reproductive potential are studied, and adequate information about the prevalence and causes of male infertility and subfertility can be obtained.