Courtesy Ed Houben

Meet Ed Houben,  a unique kind of hands on sperm donor who sleeps with women to help them conceive naturally. So far has recorded fathering 87 children and five more kids are on the way.

Houben, 42, looks more like the Dutch historian that he is rather than a sex machine, something that he readily admits. He also admits that he "barely had sex" when he began donating his sperm a decade ago.

"Ten years ago, I was not exactly David Hasselhoff in Baywatch," he confessed to ABC News by phone from his home in Maastricht, Holland.

Houben initially donated his sperm the traditional clinical way at a sperm bank, but soon reached the bank's legal limit for donations. He then went private, offering his services on the internet. And like many of the online donors, he also became an experienced practitioner in "natural insemination"- in other words,  sex.

"From my own experience, statistically natural insemination is faster," Houben says, referring to records that back his claim. "If people are coming all the way from Italy, they don't want to be trying for three years."

Houben points out that while it's easy to accuse donors of looking for cheap sex, most of the women he sleeps with aren't people he would choose as sexual partners.

"This isn't Heidi Klum coming round and saying: 'Let's do it'," he says. "It's genuine people who I would never want to hurt. I have a good old fashioned Catholic guilt feeling and I would be a candidate for therapy if I did this for the wrong reasons."

"In the old days I would gladly travel," he says, "but my job has changed and I have to be around much more. Now people to come to me." He still makes exceptions, however, if his recipients are entering a peak fertile period.

They come from all over the world. Houben claims biological offspring in Australia, Israel, Britain, Germany, Italy, Luxembourg, Belgium as well as Holland. His oldest child is 9 while the youngest is a newborn.

He is by no means a world record holder. Houben says he once watched an episode of "Oprah" about a man who had fathered 200, a number he says he'll never catch. But he has been called Europe's most prolific sperm donor, and he's happy to accept the title.

Houben meets 10 to 15 women a month.This week he's seeing only one woman from Germany, and is using time off to be with his girlfriend. He's genial, bright and witty on the subject of his pastime, but what his recipients value most of all is his commitment.

According to his own data, Houben succeeds in producing a child 80 percent of the time.

All his recipients must show medical records showing they are free from diseases and they don't use illegal drugs.  Houben has his own medical paper work with a semen analysis (spermiogram) with a very good 100 million sperm count. "According to World Health Organization, my sperm is above average quality," he boasts.  A sperm count that does not go beyond 20 million indicates a man is far less likely to get a woman pregnant.

As it's illegal to sell sperm in Holland, so Houben's donations are a vocation not a career.

Donor numbers have been declining dramatically in Holland since anonymity for sperm donors was ended in 2004. Those affected by the shortage the most, particularly lesbian couples, single women and those starting a second family have been turning to the internet. For them the options are costly private treatments of artificial insemination or the do it yourself approach. And there is no doubt that the online sperm donation scene is growing. Houben started placing ads on a growing number of websites and online forums to continue his "mission" after he had filled his state allowance of 25 pregnancies.

SpermaSpender.de. in Germany is one of the websites Houben uses to connect with childless women desperate to conceive. It is a user friendly website that works like a dating site, only women are registered as "looking for a donor" and men as "donors." SpermaSpender.de has more than 20,000 members from all five continents, including thousands of donors.

"We have around 180 pregnancies a year," claims Joacim Welz, owner of the website. "Every second day I get a baby."

Last May, Houben invited more than 20 of the children he's helped create to his home for his once a year reunion.

"I always felt the child should have a right to know where it comes from," he says, and adds that he hopes that his openness on the subject will help to tackle the stigma surrounding sperm donation.

He gets parents to sign documents waiving legal claims to child support, but experts say these would be invalid in the hands of a good lawyer. "If I were a millionaire, I would support them all, but I am not," Houben says.

He's not sure how long he'll continue adding to the world's population, but he can't see a reason to stop yet. Houben does have a Spanish girlfriend now - someone who originally came to him looking to get pregnant - and she is happy for him to continue.

"But," says Houben "we might start living together and have a family together. And then that's the end."