Infertility affects about 15 percent of couples and half of these cases come from men. There are many different reasons for it, including misshapen sperm, low sperm count, and blockages that prevent sperm from leaving the body. It's rarely easy to pinpoint the problem: Male fertility is so complex that we don't even know what the most common cause of infertility is, says Dr. Thomas J. Walsh, director of male reproductive and sexual medicine at the University of Washington Medical Center. Walsh says the first step in addressing infertility is talking with your doctor, which will generally lead to an examination of your health and lifestyle and a semen analysis. "It's a pretty hopeful condition, as long as you seek the right care," he says. From there, treatments vary. Potential fixes range from increasing exercise to hormone therapy. Here are the most scientifically sound male infertility treatments available today.