Medical Reports: Healthcast: Lab-grown sperm

WSVN -- Stephen and Melissa James got their wish for a biological child when Katie was born.

Stephen James: "Now that I have a daughter, it's the most amazing thing in the world."

Katie was born through IVF -- in vitro fertilization.

Melissa James: "It would be nice for her to have somebody to grow up with."

Studies show that male infertility is the cause behind one-third of infertile couples. Now, German researcher Wolfgang Engel wants to take the man out of the equation.

Wolfgang Engel , M.D.: "We are trying to generate sperm, artificial sperm, and we hope that we can help these couples."

Engel is actually growing sperm in his lab. He's already produced mice with sperm made from embryonic stem cells.

But even if this proves successful in humans, it won't give infertile men a biological tie to their children. It would be no different than using donor sperm.

So now he's growing sperm from very early cells -- called germ cells -- taken from a man's testicle. This too was successful in mice.

Wolfgang Engel, M.D.: "If it works in the mouse, I'm sure it will also work in the human."

Engel's next challenge? To grow sperm taken from a female germ cell, which could then be used to fertilize another woman's egg.

As long as it's safe, Stephen and Melissa welcome the research. In the meantime, they'll keep trying for baby number two with what now seems like the old-fashioned way -- IVF.

Even if the ethical arguments against lab-grown sperm win out, in the long run, the research will continue moving forward. Dr. Engel says, at the very least, studying the way sperm cells grow in the lab could help with future treatments for male infertility.