An editorial in a major Canadian medical journal Monday urges doctors to conceal the gender of a fetus from all pregnant women until 30 weeks to prevent sex-selective abortion by Asian immigrants.

A separate article in the same issue of the Canadian Medical Association Journal warns that Canada has become "a haven for parents who would terminate female fetuses in favor of having sons" due to advanced prenatal testing and easy access to abortion.

"Female feticide happens in India and China by the millions, but it also happens in North America in numbers large enough to distort the male to female ratio in some ethnic groups," said the editorial by interim editor-in-chief Rajendra Kale.

While few studies have been done to assess how frequent the practice may be among immigrant communities in Canada, the editorial points to research that suggests sex-selection is more common among immigrants from India, China, Korea, Vietnam and the Philippines who already have at least one daughter.

It cites US census data from 2000 that shows male-biased sex ratios among US-born children of Asian parents, and a study of 65 Indian women in the US from 2004-2009 that showed 89 percent of them terminated pregnancies with female fetuses.

Kale told AFP he believes that several hundred sex-selective abortions take place in Canada each year.

"Should female feticide in Canada be ignored because it is a small problem localized to minority ethnic groups? No," said the editorial written by Kale, a Mumbai-born neurologist.

"The solution is to postpone the disclosure of medically irrelevant information to women until after about 30 weeks of pregnancy."

Canada in 2004 outlawed fertility practices that would increase the likelihood that an embryo will be a certain sex, or that would identify an in-vitro embryo by sex for any reason other than to diagnose a sex-linked disorder or disease.

Kale said the Canadian medical establishment needs to go further, and make express rulings that would ban fetal sex disclosure before seven months, when it is too late for an abortion.

He added that doctors should nevertheless "avoid painting all Asians with the same broad brush and doing injustice to those who are against sex selection," but called for collective cooperation by women of all races.

"The execution of a 'disclose sex only after 30 weeks' policy would require the understanding and willingness of women of all ethnicities to make a temporary compromise," he wrote.

"Postponing the transmission of such information is a small price to pay to save thousands of girls in Canada."

The Canadian Medical Association, the country's largest doctors' group with 70,000 members, stressed that editorial viewpoints are not necessarily those of the CMA.

Kale's controversial proposal was welcomed by conservative groups but opposed by the pro-choice advocates who warned that the debate extends much further than sex-selective abortion in minority groups.

"We would absolutely approve of such a ban," said Gwendolyn Landolt, national vice-president of REAL Women of Canada. "Is it a right to know the gender of your child if you are going to use this information to kill it?"

Alexia Conradi, head of the pro-choice Women's Federation of Quebec, agreed that abortive sex-selection is "unacceptable," but questioned the motivation of those who support formal measures to prevent it.

"You have to wonder if the act of withholding information is a good thing when the matter is being raised by conservatives in the US and Canada whose goal is to quietly roll back abortion rights."

According to Jessica Arons of the left-wing Washington think-tank the Center for American Progress, the issue raises difficult questions for women's advocates.

"Any types of restrictions on abortion are met with skepticism by the pro-choice community generally," she said.

"A more appropriate intervention with sex-selection is to do more education, especially if we are talking about son preference, rather than seek to limit women's choices or access to information."

Medical ethicist Sam Packer told AFP that any proposal to curb women's right to information would face steep opposition in the United States.

"It is a slippery slope," said Packer, ethics chair at New York's North Shore-Long Island Jewish Health System.

"To respect other people's cultural and religious views is why we started this country," he added.