Climate, “every degree more risk for male fertility”: andrologists alarm

In Italy, the latest ISTAT data certify, with just over 400,000 births in 2020, the country’s demographic decline and global warming may also be to blame: “Each additional degree risks reducing male fertility”. The Italian Society of Andrology (Sia) has raised the alarm on the occasion of the Cop26 underway in Glasgow. The average number of spermatozoa in men – andrologists reveal – today is halved compared to forty years ago and one in 10 Italians is now infertile. An effect that could also depend on climate change. It is in fact known – recalls Sia – that the increase in temperature damages the male reproductive system, much more than the female one: in some animal species, an increase of a few degrees in external temperatures can halve fertility and experts they fear that this is happening also for humans. “Studies on animals – explains Alessandro Palmieri, president of Sia and professor of urology at the Federico II University of Naples – for example on butterflies and beetles, show that the increase in temperatures is probably contributing to the extinction of some species because the male reproductive system and spermatozoa in particular are very sensitive to heat. In some cases, sperm production has been seen to drop by 3 quarters and fertilization capacity has collapsed: only a third of the spermatozoa remains vital, the majority die before they can fertilize the female gamete. Furthermore, the negative effects are also passed down on eventually generated offspring that is less fertile, with a 25% reduction in reproductive capacity “.