New study shows: Western men have fewer and fewer sperm in their ejaculate. Urologists give the all-clear: concerns about inability to conceive are unfounded
A new study on male fertility, published in the journal “Human Reproductive Update”, is currently causing a stir. The research by medical doctor Hagai Levine and his team from the Hebrew University of Jerusalem shows that the sperm count of men from western countries continues to decrease. According to the scientists, the number of sperm per milliliter of sperm has dropped by about 52 percent. The researchers even reported a decrease of almost 60 percent in the total number of sperm per ejaculation. Nevertheless, the German Society for Urology (DGU) does not see the ability to reproduce in western industrialized nations to be at acute risk.
For their investigation, the authors evaluated 185 available studies from 1973 to 2011 and thus viewed the data of around 43,000 fertile men and men with fertility problems without other known medical conditions. They differentiated between countries with a western lifestyle - including Europe, North America, Australia and New Zealand - and the rest of the world, especially South America, Africa and Asia, where the study found that no such decline was observed. However, no consideration was given to how healthy the individual sperm of the participants were. It is also unclear what causes the decrease in sperm. Nevertheless: Among experts, the study is considered the best recalculation currently available. And it suggests that the sperm count of Western men will continue to decrease in the future, possibly also as an indication of other health risks.
But what does the result of the meta study mean in terms of male fertility? “I don't think the men have to worry. The changes shown are all in a highly normal range, ”reassures Prof. Dr. med. Sabine Kliesch, Chair of the Patient Academy and the Andrology Working Group of the German Society of Urology. "A limitation of fertility is not to be expected due to the statistically observed changes."
The specialist in reproductive medicine and andrology advises not to overestimate the data collected. Among other things, because it is normal for men to experience fluctuations within the normal range again and again - without this having to indicate a pathological deviation. In addition: “The number of sperm that moves forward is more decisive than the absolute number of sperm. Only these are able to reach the egg cell during natural fertilization. There is no data on this in this study, ”says Prof. Sabine Kliesch. You also have to take into account that the measurement methods have improved significantly over the years. "It is quite conceivable that the measured trend also resulted in part from the possibilities for more precise quality control," says the andrologist.
But even if the all-clear can be given with regard to the fertility of men, the result of the study must be taken seriously. "The subject of further investigations should be what mechanisms are behind the decline in sperm and to what extent they also affect men's health in general," says Prof. Christian Wülfing, press spokesman for the German Society for Urology. “The influence of lifestyle factors such as obesity, stress and smoking is becoming the focus of the discussion, as are possible risk factors from the environment, such as chemicals. Also take into account the age of men and diseases that can affect sperm and ejaculate quality, including testicular cancer, prostate cancer or testicular abnormalities. ”