An international study on the causes of male infertility with the collaboration of Jaime Mendiola, a researcher at the University of Murcia (Spain), concludes that 15% of men are currently infertile.
Among them, 40% of the cases are due to unknown causes; 15% are due to some genetic disorder linked to a fertility problem; and 30% are patients with altered seminograms without genetic cause.
Historically, the responsibility for human fertilization has always fallen on women. With the delay of motherhood and the increase in complications to achieve pregnancy, research on reproduction has focused its efforts on the female factor.
Despite this, in recent years the science of fertility has begun to look seriously at men and, specifically, their semen. The latest scientific review published in late 2017 in the journal ‘Human Reproduction Update’ states that Western men’s semen is worse now than it was 40 years ago. Sperm concentration has risen from an average of 99 million sperm per millilitre in 1973 to 47.1 in 2011, a decline of 52.4%.
It remains to be seen how these data will affect the future of reproductive capacity. Although the decrease in natural conception rates that could be expected given the decrease in sperm counts has not been observed for the time being, the alerts regarding the evolution of male fertility are beginning to sound.