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Dr. Kashanian responds to the trend in declining sperm

Temporal trends in sperm count: a systematic review and meta-regression analysis. 

Hagai Levine, Niels Jørgensen, Anderson Martino-Andrade, Jaime Mendiola, Dan Weksler-Derri, Irina Mindlis, Rachel Pinotti, Shanna H. Swan.  Human Reproduction Update,  Published: 25 July 2017 

Semen parameters have long been touted as a barometer for overall men’s health.  The recent meta-analysis published by Levine et al in Human Reproduction Update chronicling a progressive decline in sperm count are as concerning in relation to fertility as they are to a male health perspective.  Recent studies have correlated decreased semen parameters with increased male morbidity and mortality.  But with those studies, as well as with this recent meta-analysis, the question remains cause and effect. 


It is difficult to properly attribute the etiology behind the progressive decline in sperm count.  For one, this may be related to an increasing co-morbid young population with roughly 1/3 of US men being overweight and 1/3 being obese.  This, along with an increase in westernized male exposure to pesticides, environmental factors, illicit drug use and tobacco could help to explain this finding. 


This subject has and will continue to be an important topic of discussion and more research is needed to identify possible causes and implications. 



James A. Kashanian, M.D.

Assistant Professor of Urology and Reproductive Medicine

Center for Male Reproductive Medicine & Microsurgery Weill Cornell Medicine
525 E 68th Street
New York, NY 10065