Examining The Issue

"If we will not change the ways that we are living and the environment and the chemicals that we are exposed to, I am very worried about what will happen in the future."
"Eventually we may have a problem, and with reproduction in general, and it may be the extinction of the human species."
Dr. Hagai Levine, epidemiologist, Hebrew University-Hadassah Braun School of Public Health and Community Medicine, Jerusalem

"I’ve never been particularly convinced by the many studies published so far claiming that human sperm counts have declined in the recent past." "However, the study today by Dr Levine and his colleagues deals head-on with many of the deficiencies of previous studies."
"The debate has not yet been resolved and there is clearly much work still to be done. However, the paper does represent a step forward in the clarity of the data which might ultimately allow us to define better studies to examine this issue."Professor Allan Pacey, Sheffield University, Great Britain 

"The extent of the decline in sperm counts in the Western world revealed in this study is shocking."
"As the authors point out this has major implications not just for fertility but for male health and wider public health."
"[It remains] an unanswered question [whether future generations of children will reflect this kind of reproductive damage resulting from current male declining sperm counts]."
"This study should act as a wake-up call to prompt active research in this area."
Dr. Daniel Brion, honorary professor, clinical embryology and stem-cell biology, Department of Reproductive Medicine, University of Manchester

A doctor is silhouetted as he walks past a poster in a Rome fertility clinic. Alessia Pierdomenico / Reuters

This new study through the Hebrew University and the Icahn School of Medicine at Mount Sinai, New York of which Dr. Levine is the lead author, points out that men's sperm counts have fallen by close to sixty percent since the 1970s. And modern life, it would appear, may be regarded as the fuel that led to this volatile fertility crisis. Experts point to chemicals, pesticides, stress, obesity and tight underwear, reflecting the major factors responsible for the crisis.

The researchers engaged in this project tracked over 40,000 men to reach their conclusions. Their study results were published in the Human Reproduction Update journal. And what they point out is that this startling issue of lowered sperm count could be a harbinger of damage to men's health extending beyond fertility, since lower sperm count has linkage to higher death rates and increased potential of suffering other diseases.

Earlier studies have previously linked declining sperm quantity and quality to chemical and pesticide exposure, along with lifestyle factors that include stress and obesity. But this new research is considered to represent the first systematic review of trends in its examination of over 180 studies in a four-decade period to reach the conclusion that since 1973 overall sperm counts in the West have fallen by 59 percent, and sperm concentration by 52 percent.

"It shows the decline is strong and that the decline is continuing", warned Shanna H. Swan, one of the new study's authors. She added that it was her hope that this broad meta-analysis of previously published literature would stamp 'settled' to uncertainty surrounding the collapse of sperm count and its drivers. The decline is worldwide, but it is in the Western world where it appears to be most pronounced.

The emphasis on men in the West being hit particularly hard, appears to validate the exposure to chemicals connection as cause.

But then, according to Richard Sharpe of the MRC Centre for Reproductive Health at University of Edinburgh, delays in pregnancy with an increasing number of would-be parents prepared to wait while the female partner accomplishes other aspirations like completing her education or starting a business, then beginning a family over age 30, coupled with the declined sperm count of her male partner delivers twice the impact in conception difficulties.

Average sperm count concentration has fallen from 99 million sperm per ml to 47 million per ml, according to the World Health Organization which classes low sperm concentration in the field of less than 15 million per ml. Currently over 15 percent of young men have sperm counts that are sufficiently low to be interpreted as within the realm of impaired fertility, and that number is expected to grow in the future.

Beyond the issue of difficulty in conceiving, resulting from low sperm count and quality, the larger implications are again linked to cardiovascular issues, obesity, cancer, leading to higher rates of hospitalization and consequent mortality. At the present time, men's life expectancy is on the increase as a result of rapid advancement in medical care, nutrition and sanitation.

Expectations among experts, however, envision that trend reversing, should the issue of lower sperm count continue.

The concentration of sperm in the ejaculate of men in western countries has fallen by an average of 1.4% a year, leading to an overall drop of just over 52%, say researchers. Photograph: Alamy