A new study published in the International Journal of Andrology reveals that semen quality has significantly deteriorated during the last ten years in Finland, a country that previously was a region with high sperm counts. At the same time, the incidence of testis cancer in the Finnish population showed a remarkable increase, following the worrying trends observed in several countries in Europe and the Americas.

Led by Jorma Toppari, MD, PhD, of the University of Turku, researchers examined three cohorts of 19 year old men between the years of 1998 and 2006. The men that were born in the late 1980s had lower sperm counts than those who were born in the beginning of the 1980s. The total sperm counts were 227 million, 202 and 165 for men born in 1979-81, 1982-83 and 1987, respectively. Less than 10 % of sperm are structurally normal, and the number of morphologically normal sperm declined from 18 million to 11.

At the same time, the younger and more recently born men also had higher incidences of testis cancer than the older generations. The incidence rate is many fold higher for Finns born around 1980 compared with men born around 1950.

The underlying cause for these simultaneously occurring adverse trends remains unknown. However, the rapid change strongly points to environmental reasons. Endocrine disrupting compounds acting during development have been hypothesized to be a cause.

"Our findings further necessitate the efforts to identify reasons for the adverse trends in reproductive health to make preventive measures possible," Toppari notes.