But what happens to the sperm of the Swiss?

Numerous epidemiological studies carried out in Europe in recent decades tend to show a decline in the quality of sperm, in particular its concentration of spermatozoa, which decreases over the years. For the first time in Switzerland, a team of researchers wanted to study the quality of Swiss sperm. 2523 men between the ages of 18 and 22 from different cantons took part in the research. Result: with an average concentration of 47 million spermatozoa per ml, Swiss sperm lags behind the European average, which is between 41 and 67 million per ml.

Based on the WHO fertility references, we also find that only 38% of Swiss people have sperm parameters (concentration, mobility and morphology) above established standards. “Swiss sperm indeed seems to be of lower quality than the international average,” notes Dr. Fabien Murisier, biologist at the CPMA fertility medical center in Lausanne. But it is difficult to say if it has deteriorated over the years, because there are no studies carried out over the long term.

An impact on fertility

What is the link between sperm quality and testicular cancer?

In Switzerland, around 460 new cases of testicular cancer are recorded each year, a prevalence that is increasing and higher than in our European neighbours. "Several studies have shown that people with poor sperm quality were at greater risk of developing testicular cancer," says Dr. Fabien Murisier, biologist at the CPMA fertility medical center in Lausanne. Among the hypotheses put forward to explain the correlation, that of poor development of the genital organs during the fetal period, induced by the effect of endocrine disruptors, which would lead to a greater frequency of genital anomalies, a drop in sperm quality and an increased risk of testicular cancer. "But the link remains to be clearly established, especially since testicular cancer itself may also be the cause of sperm depletion."

The correlation between poor sperm quality and infertility is however well established. Below 40 million spermatozoa per ml, "the time to achieve conception of a baby increases significantly", recalls Serge Nef, professor in the Department of Genetic Medicine and Development of the UNIGE Faculty of Medicine and author of the study. However, in Switzerland, 17% of young men have a concentration of less than 15 million per ml, an extremely critical threshold for fertility. A finding that has been reflected in recent years by the increasingly frequent use of medically assisted procreation (PMA). Between 2002 and 2016, the number of couples who benefited from it increased by 70% in Switzerland.

In recognition of #NationalNutritionMonth, check out our webinar recording for strategies on how to maintain a bala… https://t.co/bGwz7s6bM2

— Cancer and Careers Mon Tue 19 14:24:58 +0000 2018

To establish a fertility diagnosis, many parameters are measured through a spermogram, including the number, mobility and morphology of the spermatozoa. They are compared to the standards issued by the WHO, based on data from men who have become fathers naturally. “The 5% of individuals with the worst values ​​define the reference threshold, explains Dr. Murisier. This means that men who are below this benchmark are not sterile, but their chances of conceiving naturally are statistically lower.

Whose fault is it?

To explain the worrying deterioration in sperm quality, several factors are often singled out. The environmental aspect, in the first place. The role of pesticides has long been studied for their deleterious impact on sperm. Smoking also affects the quality of sperm. Studies have even established that the mother's smoking during pregnancy also heralds a drop in sperm quality in the future child. Alcohol, cannabis and an unhealthy lifestyle in general also have a negative impact, as do heat, tight clothing or a sedentary lifestyle. “The testicle is designed to operate at around 35 degrees, or 2 degrees less than the body, recalls Fabien Murisier. It is a relatively sensitive organ, where we see more quickly than elsewhere the repercussions of a poor state of health. Diabetes, obesity, hypertension can also have a deleterious impact. This is also the case for taking medication, such as certain antiepileptics or testosterone, “but it is not always possible for the patient to stop this type of treatment”.

We also know that there is a genetic component in infertility, yet naturally doomed to disappear, because without offspring it is impossible to transmit the genes involved. “However, thanks to assisted reproduction, infertile men can become fathers, and therefore possibly pass on the genetic characteristic of infertility to their sons,” explains Dr. Murisier.

On the other hand, unlike women in whom there is a decrease in the stock of ovules with age, aging does not alter the concentration of sperm so much. On the other hand, it affects the genetic quality of spermatozoa, leading to a greater risk of mutations.

Finally, there is currently no scientifically established conclusion regarding WiFi waves and mobile phones. “But screens nevertheless have an indirect impact on fertility, by replacing many sexual relations today,” concludes the biologist.

Does frequent intercourse influence sperm quality?

Based on clinical observations, the answer is “yes”. Ejaculations at close intervals make it possible to renew the stock of young spermatozoa and therefore to produce fertilizing sperm. “We have observed that in men who have had a period of abstinence of more than 10-15 days, the quality of the sperm is less good, explains Dr. Fabien Murisier, biologist at the CPMA fertility medical center in Lausanne. In the case of a course of medically assisted procreation for example, we therefore ask for an abstinence of less than 7 days and sometimes even two ejaculates less than 24 hours apart, the second often being better.

On the other hand, too high a frequency of reports risks causing the opposite effect, ie a depletion of stocks. “Having sex daily or every other day for the 5 days before ovulation is the recommendation for optimal chances of pregnancy.”

______

Published in the Quotidien de La Côte on 07/31/2019.