In the United States, 10 to 15 percent of couples struggle with fertility issues. In years past, the perception has been that an inability to conceive was attributable to problems with the woman's reproductive functionality. But researchers like Dr. Liberty Barnes at Cambridge University who recently published the book "Conceiving Masculinity: Male infertility, medicine, and identity," contradict the idea that this is a women's issue. Barnes says that of those millions of people trying without success to conceive a child, 30 percent are due female factors, 30 percent are male factors, 20 percent are a combination of male and female factors, and 20 percent of cases of infertility are simply unknown.

Barnes says infertility in men has many causes, from trauma to viruses, and numerous possible solutions, including everything from surgery to hormones. For those struggling to get pregnant, she argues, fertility can feel like a life or death issue. And there is a humorous element of the process, too, that centers around the moment a man is handed a cup, pointed to a small room, or a curtained-off area, or their car, and asked to give a semen "sample."

"Our ideas about masculinity are part of what makes this funny," says Barnes, "because we think men are supposed to be able to perform. But then as a woman, I think about how if I were in a situation where a doctor said, 'I need you to orgasm, basically, behind this curtain over here,' I'd be absolutely mortified!"

Barnes joined us from Cambridge, England to talk about the man's role in conception troubles.