TORONTO - Dr. Rajendra Kale calls it the most severe and repugnant form of discrimination against females -- and he wants to see it stopped.

The practice of aborting a female fetus after the parents learn the sex of their developing child through ultrasound is not as widespread in Canada as in such countries as India and China, where a cultural and often religious preference for boys has led to the estimated destruction of millions of females in the womb.

But Kale says smaller numbers in Canada, estimated in the thousands, are no reason to ignore such gender-based violence.

"Female feticide devalues women completely," said Kale, interim editor-in-chief of the Canadian Medical Association Journal. He wants to see doctors withhold information about the sex of a child in the womb until 30 weeks' gestation to prevent "an unquestioned abortion" because parents prefer a boy.

Kale said research in Canada has found the strongest evidence of fetal sex selection among some Canadians of Asian descent, including people from India, China, Korea, Vietnam and the Philippines.

"What this means is that many couples who have two daughters and no son selectively get rid of female fetuses until they can ensure that their third-born child is a boy," he writes, while stressing that not all Asian-Canadians condone nor engage in the practice.

In an editorial in Monday's issue of the CMAJ, entitled "It's a girl -- could be a death sentence," Kale puts the onus squarely on the medical community to try to halt sex-based abortion.

He calls on the provincial colleges that regulate physicians to rule that health-care professionals should not reveal a baby's sex to any woman before 30 weeks of pregnancy.

"I'm arguing that the sex of the fetus is medically irrelevant information because it does not affect care in any way whatsoever, except in the very rare instance where you have sex-linked genetic diseases," Kale said in an interview.

"Doing so should be deemed contrary to good medical practice. Such clear direction from regulatory bodies would be the most important step toward curbing female feticide in Canada."

Kale said waiting to divulge the sex of the fetus until after the start of the third trimester would still give parents who want to know whether they are having a boy or a girl enough time to prepare their nursery or purchase appropriate clothing.

"So you're just postponing the point at which you deliver that information," he said.

While the College of Physicians and Surgeons of Ontario, for instance, does not have a specific policy on sex-selected abortion, the regulatory body does advise its members that it is "contrary to good medical practice to use ultrasound only to view the fetus to obtain a picture or video of the fetus or to determine the gender of the fetus," spokeswoman Kathryn Clarke said by email.

The B.C. regulatory body likewise states that testing to identify fetal sex should not be used to accommodate societal preferences, that terminating a pregnancy for an undesired sex is repugnant and it is unethical for a doctor to facilitate such a course of action.

The Society of Obstetricians and Gynaecologists of Canada said Kale's proposal runs counter to the medical group's policy that a patient's request for disclosure should be respected.

"Examination of the fetal genitalia is a recognized part of the routine second-trimester obstetric ultrasound," the SOGC said in an emailed statement. "Providing patients with results of diagnostic imaging procedures is part of the Canadian standard of care, and fetal sex determination and disclosure should not be exempt.

"Therefore, the SOGC believes it is the right of the patient to be informed of the gender of their fetus, and that this information should not be withheld."

The professional organization also said Kale fails to acknowledge cultural values that lead some people to seek pregnancy termination based on the sex of the fetus and does not take into account biochemical testing products that can give expectant parents a highly accurate fetal sex determination as early as eight weeks into pregnancy.

"The SOGC in no way condones pregnancy termination based on non-medical reasons, such as the gender of the fetus. The SOGC feels strongly that it is the cultural values and norms in specific segments of the Canadian population that must change to ensure that females are not confronted with procedures and intolerant environments before or after they are born."

Though reasonably intentioned, Kale's call for policy changes is likely a moot one in any case, said Bernard Dickens, professor emeritus of health law and policy at the University of Toronto.

During deliberations of the Royal Commission on New Reproductive Technologies, it was suggested that withholding the gender of a fetus could be a way to reduce the possibility of sex-based abortion, but the control device wasn't built into the subsequent legislation, the 2004 Assisted Human Reproduction Act.

Dickens suggested that was likely because the Supreme Court of Canada, in the case of McInerney v. MacDonald, had ruled in 1992 that patients' medical information is not owned by their physicians and must be surrendered at a patient's request.

"If the patient persists and wants to know the sex ... the doctor cannot lawfully deny the patient the information," he said.

For Kale's goal to be fulfilled, new legislation would be needed that contradicts the Supreme Court decision, but introduction of such a law would no doubt trigger a challenge based on the Charter of Rights and Freedoms, Dickens said.

A challenge could be based on contravention of a number of enshrined rights, including discrimination on the grounds of the right to security of the person, that women have the right to continue only wanted pregnancies.

There are also pockets among some of Canada's immigrant Asian communities that hold strong religious beliefs that a male heir is necessary to carry on the family name and to perform certain rites to ensure deceased parents have a proper afterlife.

"And, of course, this could trigger a Charter claim of denying religious convictions or violating the anti-discrimination provision of the Charter," Dickens said. "So any legislation could trigger a Charter argument on that sort of ground."