Scientists from the University of Geneva have discovered that Swiss men have the worst quality sperm in Europe, with 17 percent of Swiss men being considered “sub-fertile” in accordance with guidelines from the World Health Organization (WHO).
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The study aimed to assess the quality of semen and male reproductive health in Switzerland. It employed a nationwide, cross-sectional study of 2,523 young men aged 18 to 22 from all areas of Switzerland who were recruited into the army.
The semen volume, the concentration of sperm, and the sperm’s motility and morphology were analyzed, along with the anatomy of the genital area and testicular volume being recorded.
‘A critical state’
The average sperm count for a European man ranges from 41 to 67 million sperm per milliliter (ml), but this new study revealed that Swiss men have an average sperm count of just 47 million per ml.
Andrologist Dr. Alfred Senn co-authored the study and said, “the sperm quality of young men in Switzerland is in a critical state and their future fertility will in all likelihood be affected.”
In contrast, men from Lithuania, Estonia, and Spain are thought to have the highest quality sperm, but as research of this nature is carried out via different methods in each country, it is hard to compare sperm quality directly between European countries.
For the first time, a systematic sampling among young men has confirmed that semen quality is affected on a national level. The median sperm concentration measured is among the lowest observed in Europe.”
Results showed that 43 percent of the men included in the study had less than 4 percent morphologically normal sperm cells, and 62 percent had “one or more semen parameters that fell below the WHO thresholds.”
Additionally, less than 40 percent of sperm cells were motile, and overall, just 38 percent of Swiss men had sperm concentration, motility, and morphology values that were equal to the thresholds set out by the WHO.
“Low semen parameter values can reflect a man’s fertility, when a combination of values are low, a man’s ability to conceive is at risk,” explained lead author of the study Rita Rahban, who was involved in realizing the research explained:
“It’s important to understand that the time needed to conceive increases significantly if a man has a sperm concentration below 40 million sperm per ml.”
The study also gathered data on testicular cancer incidence rates, taken from regional Swiss registries, and it was discovered that a higher proportion of men with a low sperm count had been exposed to in utero maternal smoking.
Testicular cancer cases have ‘grown steadily’
Links have been made previously between an increased incidence in testicular cancer and lower quality semen. Scientists believe that altered testicular development at the fetal stage is likely to be the cause of poor quality sperm and its links with testicular cancer.
When analyzing testicular cancer incidence, results showed that the incidence rates had increased from 7.6 cases per 100,000 men in 1980, to 10.4 in 2014.
“For 35 years, testicular cancer has grown steadily to over 10 cases per 100,000 men, which is very high compared to other European countries,” Professor Nef said.
“Sperm quality is generally lower in countries where the incidence of testicular cancer is high.”
Countries with better sperm counts including Spain and Estonia were also found to have lower testicular cancer incidence rates, but a definitive link between testicular cancer and a lower sperm count as a consequence has yet to be found.
Between 2002 and 2010, the number of couples experiencing infertility and seeking assisted reproductive technologies has doubled from 3,000 to over 6,000 a year.
Environmental and lifestyle factors could be responsible
Professor Nef said that several European laboratories have hypothesized that environmental and lifestyle factors could be responsible for a significant and surprising decrease in sperm counts in industrialized countries.
These laboratories have been investigating whether pesticides, smoking, alcohol consumption, taking drugs, or being overweight could be responsible for causing the low sperm counts in Europe, but the exact reasons have so far evaded researchers.
The study concludes with a statement saying that further and more refined studies should be carried out to improve the understanding around environmental and geographical factors that may affect fetal development and semen quality in later life. Additionally, more studies are needed to determine how severely compromised Swiss men’s fertility is.
Rahban, R., et al. (2019). Semen quality of young men in Switzerland: a nationwide cross‐sectional population‐based study. doi.org/10.1111/andr.12645.