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Sperm count decline may be sign of greater problems

Doctors encourage men and women to look at lifestyle and environment

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Researchers have found a 50 to 60 percent decrease in sperm count.
Helen Adams | | August 25, 2017

A report noting a dramatic drop in sperm counts should be a wake-up call for everyone, says fertility specialist John Schnorr

“You’ve got to think there are extrinsic factors that are causing that to happen. And that has implications not only for men but also women,” the MUSC Health doctor said. “What men are exposed to, women are also exposed to in the community and the environment. This is a negative predictor for overall health of human species, and something we need to pay attention to.”

The study, published in Human Reproduction Update, took a big-picture look at data from almost 200 previous studies and found a 50 to 60 percent decline in sperm count among men from North America, Europe, Australia and New Zealand.

“I think that’s pretty meaningful, and frankly, concerning,” Schnorr said. “Why is there a decline? It’s not likely to be genetics making them go down. And we can’t forget about the contribution of the maternal environment on the health of a male. Even when he’s 30 or 40 years of age, his maternal environment can still be detrimental.” The maternal environment refers to what the baby was exposed to from the mother during pregnancy. 

Dr. John Schnorr says multiple factors may be causing the drop in sperm count. Photo by Sarah Pack

So what, specifically, might be the culprits? Schnorr has some ideas. “My bet is, part of this is tobacco and part is alcohol and part is obesity. All those negative factors.”

There’s research to back up those concerns. 

  • Tobacco: Brazilian researchers found men who smoked had a higher percentage of DNA damage than men who didn’t, which affected their sperm quality. 
  • Alcohol: A Danish study found men who were “habitual” alcohol drinkers had both lower quality semen and hormone changes.
  • Obesity: An analysis published in 2012 found overweight men were at “significantly increased odds” of oligozoospermia and azoospermia, both of which are linked to male infertility. 

Schnorr also suspects certain chemicals may be affecting sperm quality. “We all know about BPA, which is a plasticizer,” he said. BPA, or bisphenol A, is being studied as a possible cause of infertility. “But it would be naïve to think there’s not another 200 chemicals we don’t yet know about that we’re taking into our bodies,” Schnorr said. “We may find out in 20 years that they’re likely playing a role in this, too.”

Demetri Spyropoulos, a researcher and professor in MUSC’s Department of Pathology and Laboratory Medicine, agrees. He said the low sperm count report is just the tip of the iceberg. 

“Mike Skinner’s group published work showing that pregnant rats exposed to commonly used fungicides had sons with low sperm count, but those sons that successfully mated had sons of their own that also had low sperm counts,” Spyropoulos said. Skinner is a biological sciences professor and researcher at Washington State University. 

“His big finding is that hormone, or endocrine, disruptors don’t only reduce sperm count, they also make defective sperm that pass this defect on to their sons.”

Spyropoulos’ own research also focuses on chemicals that may be endocrine disruptors that drive obesity and metabolic syndrome, and he said they are found in a lot of places – even stool softeners, some soft drinks and fruit flavored drinks, homogenized milk and personal care products. 

His advice: “Don’t focus on the symptom — taking testosterone or other male-enhancement supplements. Focus on the source of the problem — reducing your exposures to the hormone disruptors.”

So, what can couples who want to have children do? 

Schnorr, the fertility specialist, directs the Division of Reproductive Endocrinology at MUSC. He helps couples who have had trouble having children at both MUSC Health Women’s Care Fertility Services and Coastal Fertility Specialists.

“If a couple came in with fertility problems, we’d spend time figuring out what the sperm count is, what the egg count is, are the tubes open, and what the hormone levels are. Once we know that, sometimes it’s just fixing the underlying abnormality.”


If the abnormality involves the woman, he said, there are several options, depending on the issue. “We can regulate women’s menstrual cycles. We can open fallopian tubes. We can do surgery on the uterus.” He and his team also can give medicine to help women ovulate and then concentrate the sperm to be inserted into the woman’s uterus to help her conceive.

In vitro fertilization is another option. “We take out a woman’s eggs after she’s been on special medications and fertilize the eggs in a test tube to make embryos. We put them back in her uterus after they’ve developed.”

Women who delay starting families until later have options, too. “If you’ve chosen not to get pregnant because it’s not the right time, we have techniques to buffer that by freezing eggs and other things. Around 32 to 33 yeas of age you should be thinking in that direction if you’re far from the time when you want to conceive.” 


Schnorr said the male factor is the culprit in about a third of all infertility cases. First, the men need to be examined and to undergo hormone testing. Then, they may need hormone treatment, surgery or another infertility treatment. 

“With current technology, most male factor infertility can be successfully treated,” Schnorr said.

His advice: “Men should live a healthy life by keeping their weight down, eliminating tobacco and marijuana use and minimizing alcohol consumption.”

Vitamin D research leads to first-of-its-kind recommendation for pregnant women (MUSC News, May 4, 2017)

Oil study raises 'red flag' about commonly-used compound (MUSC News, July 2, 2015)



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