Medical experts are at a loss to explain why Sperm Count among western Men tumbled down by almost 60 percent since the 1970s. Although they could not pinpoint the exact cause behind the medical phenomenon, the alarming level of decline creates a big problem for mankind because of its potential to result in the extinction of the human species.

Investigators from multiple international universities performed an analysis on 185 academic studies that confirmed a steady decline in sperm count over the last 40 years. Besides showing no evidence of leveling off, the analysis implied the sperm counts of a growing proportion of men are below the thresholds for reduced fertility or full-fledged infertility, BBC reported,

Reasons behind the decline

According to Dr.

Hagai Levine, the lead researcher of the study - published on July 25 in the Human Reproduction Update journal - among the reasons believed behind the drop in sperm counts are biological, environmental, and psychological. As life becomes more difficult and methods of population control became readily available, couples generally were not having as many children as their parents and grandparents did. The employment of more women as part of the global push toward gender equality contributed to the lesser number of births even if a lot of employers do not fully accommodate family life and employment of female workers.

Levine identified the exposure to chemical and pesticides as among the environmental factors that could affect sperm count.

He also cited bad lifestyle habits such as poor diet and smoking as contributory factors. For psychological factors, Levine did not rule out stress.

Exposure inside the womb

Shanna Swan, a senior researcher and professor of environmental medicine at the Icahn School of Medicine at Mount Sinai in New York City, said those factors cited by experts temporarily reduce the fertility of males.

She believes the real damage comes from exposures that happen inside the mother's womb.

She explained that when a mother smokes, her son will have lower sperm count whether he would smoke or not. "That says what a man is exposed to when he's in utero is important. The mother's exposure will cause a change that stays with the man his entire life," Swan explained, CBS News reported.

As a result of the lower sperm count, the man of today has an average of 66.4 million sperm per milliliter of semen. Forty years ago, the average was 92.8 million per milliliter, Dr. Avne Hershlag, the chief of Northwell Health Fertility in Manhasset, New York, said.

The study covered 43,000 men in Europe, the United States, New Zealand, and Australia where the declines in sperm count are strong, significant, and continuing, Swan said. She pointed out that a previous study, now 25 years old, observed a decline in sperm count when the results of the research were published in 1992. The drop at that time was 50 percent over five decades. She warned, "The story has not changed over the past 25 years. Whatever is going on is not transient and it's not disappearing."