Less sperm equally less fertility?

New study shows: In Western men, there are fewer and fewer sperm in the ejaculate. Urologists give the all-clear: worries about inability to produce are unfounded
A new study on male fertility published in the journal "Human Reproductive Update" is currently causing a stir. The studies of medical scientist Hagai Levine and his team of the Hebrew University of Jerusalem show that the sperm count of men from Western countries continues to decrease. According to the scientists, the sperm count per milliliter of semen has dropped by about 52 percent. In the total number of sperm per ejaculation, the researchers even reported a decline of nearly 60 percent. Nevertheless, the German Society for Urology e.V. (DGU) does not see the fertility in western industrialized nations at risk.

Image: Tatiana Shepeleva - fotolia

For their study, the authors evaluated 185 existing studies from the years 1973 to 2011 and thus looked at the data of about 43,000 fertile men and men with problems of fertility without further known pre-existing conditions. They distinguished between countries with Western lifestyles - including Europe, North America, Australia and New Zealand - and the rest of the world, especially South America, Africa and Asia, where, according to the study, no such decline can be observed. However, it was not considered how healthy the individual sperm of the participants were. It is also unclear what causes behind the sperm decline. Nevertheless, among experts, the study is considered the best recalculation that currently exists. And it suggests that the sperm count of Western men will continue to decline in the future, possibly as an indication of other health risks.

But what does the result of the meta-study mean in terms of the fertility of men? "I do not think the men have to worry. The changes shown are all in a very normal range, "explains Prof. Dr. med. med. Sabine Kliesch, Chair of the Patient Academy and the Andrology Working Group of the German Society of Urology. "A limitation of fertility is initially not expected due to the statistically observed changes."

The specialist in reproductive medicine and andrology recommends that the data collected should not be overestimated. Partly because it is normal for men to experience fluctuations within the normal range again and again - without this indicating a pathological deviation. In addition: "More decisive than the absolute sperm count is the number of sperm cells that move forward. Only these are able to reach the egg during natural fertilization. There is no data in this study, "says Prof. Dr. med. med. Sabine Kliesch. In addition, one must take into account that the measurement methods have improved significantly over the years. "It is quite conceivable that the measured trend has partly resulted from the possibilities for more precise quality control," says the Andrologist.

But even if men can be given the all-clear with regard to the fertility of men, the result of the study must be taken seriously. "Further investigations should examine which mechanisms are behind the sperm decline and to what extent they also affect the health of men in general," says Prof. Dr. med. Christian Wülfing, Press Spokesman of the German Society of Urology. "The influence of lifestyle factors such as obesity, stress and smoking is as much in the focus of the discussion as potential risk factors from the environment, such as chemicals. Men's age as well as diseases that can affect sperm and ejaculate quality, including testicular cancer, prostate cancer or abnormalities of the testes, must also be considered. "