Inside the sleek offices of Seattle Reproductive Medicine in Washington state, Dr. Paul Lin and other physicians often see Canadian couples eager to buy what isn't for sale in their own country: pregnancy with a donor egg.

They travel from British Columbia, Alberta and other provinces. They come regularly -- the clinic treats about 15 Canadians a year. And they are prepared to foot a $30,000 US bill for egg donation and in vitro fertilization.

"We provide that service for a lot of people from Canada,"says Lin, a partner at the Washington clinic. "With the publicity around egg donation, it's become more socially acceptable. . . . It's increased tremendously."

Indeed, experts say so-called fertility tourism is a growing trend in Alberta and across the country.

With tight restrictions in Canada--including a ban on the commercial sale of donor eggs as well as age limits on clients at fertility clinics--couples are travelling out of country for reproductive treatments that aren't allowed here.

"We've been calling it cross-border shopping," says Glenys Godlovitch, a University of Calgary bioethicist.

The issue was thrust into the spotlight this month when a 60-year-old Calgary woman gave birth to twin boys at Foothills Hospital.

Ranjit Hayer was too old to qualify for treatment at Canadian clinics, which typically won't accept female patients over age 50, so she underwent in vitro fertilization with donor eggs in India.

Her decision to seek treatment in another country has sparked a debate about how often fertility tourism is occurring and whether the practice carries ethical problems forgotten in the desperate quest to have children.

"People are drowning in their own pain about infertility," says Diane Allen, executive director of the Toronto-based Infertility Network.

"No one is talking to you about the ethical issues or how your children will feel about this down the road."

It's not clear how many couples are grappling with the decision to seek out-of-country fertility treatments, but observers believe the practice occurs frequently.

The Calgary-based Regional Fertility Program estimates at least 25 Albertans are travelling outside of Canada every year for the treatments.

The trend is so significant that Assisted Human Reproduction Canada, the federal agency that oversees Canadian laws for fertility treatment, held a conference on "cross border reproductive care" last month in Ottawa.

"The Agency cannot ignore concerns about the health of Canadians who access care abroad and, in particular, the health of Canadian children born as a result of those treatments," says a statement from the organization.

Experts say most fertility tourists are seeking donor eggs