Sperm Count Has Decreased By Around 60 Percent In Richer Countries

Male fertility data reveals that men in wealthier countries have seen a significant drop in sperm counts.

According to the review, between 1973 and 2011, the average sperm generated from North America, Europe, Australia and New Zealand decreased by 59.3%. The study, according to The Economist, examined the combined data from 185 different studies. Although fewer studies had been undertaken in these nations, no such pattern was observed in South America, Asia, or Africa.

However, before taking a sample, the academics used a regression analysis to account for differences in the studies' sampling methods, potential sample bias, men's age, and level of abstinence. They also discovered similar trends in underdeveloped countries as well, despite the lack of data.

"This study is an urgent wake-up call for researchers and health authorities around the world to investigate the causes of the sharp, ongoing drop in sperm count," Hagai Levine, of the Hebrew University of Jerusalem, who worked on the analysis, said in a Reuters report.

"The fact that the decline is seen in Western countries strongly suggests that chemicals in commerce are playing a causal role in this trend," says team-member Shanna Swan, of the Icahn School of Medicine at Mount Sinai, New York, in a Eurekalert article.

Chemicals in the womb, adult pesticide exposure, smoking, stress, and obesity have all been related to reduced sperm counts in the past. Previous studies that reported declining sperm counts, however, have been questioned by others as being untrustworthy.

According to Daniel Brison of the University of Manchester in the United Kingdom, previous smaller studies have been hampered by confounding variables such as the fact that laboratory methods of counting sperm have changed over time, or that the demographics of men studied have changed.

Brison said in a New Scientist report that the study solves such issues by incorporating a wide array of research of diverse design and location worldwide to establish that the sperm count reduction is likely to be true.

According to Allan Pacey of the University of Sheffield in the United Kingdom, average sperm counts are still within normal limits despite the study's findings.