SAN FRANCISCO (CBS 5) — Dave and Teri have been trying to get pregnant since they married five years ago. They both assumed the problem was hers.

“It never crossed my mind that I was infertile or would have a problem with fertility,” said Dave, sitting in their San Francisco flat.

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CBS 5 HealthWatch asked male fertility specialist Dr. Paul Turek if men think much about their fertility. “No. Men do not think about their fertility. They are immortal.” He says guys are like cars. “Men are engines that run hard almost all the time. And you can poison the engine. Not poison it but give it diluted fuel, water it down, get it out of tune somehow.”

Diluting the fuel is not something most men like to think about. But according to studies in Europe and the United States, sperm counts and sperm quality have been dropping for the past 50 years. And guys typically have no idea how the environment — or their own lifestyle — can affect fertility.

“You know you can bring a sperm count to zero taking hot baths every other day for a month,” Turek said. “It’ll take you three months to recover. It’ll go to zero.” And that’s only the beginning of his list of sperm killers. “Smoking, nicotine, tobacco…other recreational drugs are bad,” Turek said.

Turek also said excess alcohol and hair loss medications can affect sperm count, along with illnesses, opiates and stress.

Do you keep a cell phone in your pocket? Use a laptop computer on your lap? Both can possibly raise testicular temperatures enough to hurt sperm production. Some pesticides mimic hormones that disrupt sperm growth and quality. And for the first time, studies show sperm can be affected by Bisphenol-A, a chemical contained in many plastic products.

Dave and Teri are among more than 8 million couples in the U.S. with fertility problems. Nearly half the time the problem is partially or totally on the male side.

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“I’ve been on male birth control for 5 years and didn’t know it,” said Dave.

Around the time of his marriage, Dave complained of low energy to his doctor, who prescribed testosterone treatments. Testosterone and other steroids can cause sterility.

“Having a family, which I do consider part of my identity, I think we’re stuck right now,” he said. “And that, that makes me angry.”

Anger, disbelief, devastation — infertility is a diagnosis men don’t expect.

“These are things that a death in the family would induce, or losing a limb, or getting told you have cancer,” Turek said. “These are the same emotional impact. And they just never thought about it. It came from the blue sky, so it knocks ’em out.”

Turek said male infertility is often curable. His advice to men — although he said most probably won’t listen — is to treat your body as well as you treat your car. He says while women get check-ups, men should get regular tune-ups.

“The body wants to work really hard, it wants to be the best it can. And you can hurt that. Take better care of yourself.”

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