Hypertension, taking multiple medications and working a physically demanding job may impact male fertility, according to researchers at the National Institutes of Health (NIH) and Stanford University. The results were published online in the journal Fertility and Sterility.

In the study, 456 men (average age 31.8 years) in committed relationships completed preliminary interviews with questions on their reproductive history, health, lifestyle, and occupational activity and most provided a semen sample for analysis. The men were all in committed relationships and none of the couples were using contraception.

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Thirteen percent of the men who reported heavy work-related activity had lower sperm counts vs. 6% of those who reported no workplace exertion. Other work-related exposures such as heat, noise, or prolonged sitting were shown to influence semen quality. A confirmed diagnosis of hypertension increased the risk of having a lower percentage of normally shaped sperm compared to no hypertension diagnosis, but diabetes and high cholesterol did not appear to increase this risk. In addition, only 7% of the men taking no medications had sperm counts below 39 million compared to 15% who reported taking two or more medications.

While these findings indicate that these factors could be modified to improve male fertility, additional research is needed to support these results which are the first to link workplace exertion, health, and semen quality in men trying to conceive.

For more information visit NIH.gov.