Sperm count in Western men has significantly declined

Prof Dr,DRAM,HIV /AIDS,HEPATITIS ,SEX DISEASES & WEAKNESS expert,New Delhi,India, +917838059592

Sperm concentration and total sperm count has significantly and steadily declined in Western men, a study has found.Researchers from Hebrew University in Israel and Icahn School of Medicine at Mount Sinai, US carried out the first systematic review and meta-analysis of trends in sperm count.

     By screening 7,500 studies and analysing 185 studies between 1973 and 2011, they found a 52.4 per cent decline in sperm concentration, and a 59.3 per cent decline in total sperm count, among men from North America, Europe, Australia and New Zealand who were not selected based on their fertility status.Therefore, sperm count may sensitively reflect the impact of the modern environment on male health across the lifespan and serve as a "canary in the coal mine" signalling broader risks to male health, they said.

  In contrast, no significant decline was seen in South America, Asia and Africa, where far fewer studies have been conducted, researchers said.The study also indicates the rate of decline among Western men is not decreasing: the slope was steep and significant even when analysis was restricted to studies with sample collection between 1996 and 2011.

 However, the current study uses a broader scope and rigorous meta-regression methods, conservatively addresses the reliability of study estimates, and controls for factors that might help explain the decline such as age, abstinence time, and selection of the study population.

"Given the importance of sperm counts for male fertility and human health, 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, with the goal of prevention.The findings have important public health implications. First, these data demonstrate that the proportion of men with sperm counts below the threshold for sub-fertility or infertility is increasing, researchers said.

     "This definitive study shows, for the first time, that this decline is strong and continuing. The fact that the decline is seen in Western countries strongly suggests that chemicals in commerce are playing a causal role in this trend," said Swan.While the current study did not examine causes of the observed declines, sperm count has previously been plausibly associated with environmental and lifestyle influences, including prenatal chemical exposure, adult pesticide exposure, smoking, stress and obesity, researchers said.