Sperm stocks in Canada are significantly down since the federal government made it illegal to pay men for the donations, and the supply of sperm imported from the U.S. will eventually be cut off, Health Canada says.

It has been illegal to buy sperm or eggs since 2004. The change was part of Canada's new reproductive technology law, which also forbids payment for surrogacy and regulates stem cell research.

It seems without a $75 payment, most Canadian men are not interested in donating to heterosexual couples, single women looking to get pregnant or lesbian couples seeking sperm.

It is currently legal to import sperm from the U.S., where men are paid for their donation. At some point, Health Canada said, the practice will be ended.

"Unless there are amendments to the legislation allowing for some kind payment, I suspect that all sperm donation in this country will be completely shut down," said Dr. Paul Claman, a fertility specialist at the University of Ottawa.

Britain also faces a shortage of sperm donors, but the issue there is not compensation.

Rather, British men are reluctant to donate because of a legislative change that allows children conceived with donated sperm or eggs to learn the name of the donor when they turn 18.

"I think what people worry about is … somebody going to come to see me in 10 years and start demanding money," said Mark Jackson of Moss, England, who donates to infertile couples.

"Any donor doesn't need to worry because it is stated in law that you are not the guardian of this child, and you don't owe any money to this child."

With the support and funding from the British government, fertility clinics are launching an awareness campaign to encourage men to give sperm. The posters are going up where men congregate, such as rugby clubs, fire stations and ambulance halls.

Health Canada says it has no plans to launch a similar awareness campaign. Canadian fertility clinics say they should not have to pay, since they did not bring in the rules.

Surveys suggest Canadian men will step forward to donate sperm again if they're fairly compensated for lost wages and for travel to and from sperm banks.

Those rules haven't yet been worked out by Health Canada. The agency said it could be 2008 before all of the regulations governing reproductive technologies are fully implemented.