A new study finds that Indian-born women in Canada with two or more children are giving birth to more baby boys than

expected. And researchers suggest abortions related to sex selection may be a major reason.

The study says Canadian-born women in Ontario gave birth to about 105 boys for every 100 girls between 1993 and 2012, consistent with the average in most of the world.

But women who immigrated from India who already had two children gave birth to 138 boys for every 100 girls. If they already had three children, they give birth to 166 males for every 100 females.

That ratio rises to 326 boys per 100 girls for Indian-born mothers with two daughters who had an abortion preceding her third birth.

It was 409 boys for every 100 girls if the mother had more than one abortion.

Lead author Marcelo Urquia of Toronto's St. Michael's Hospital says it's illegal in Canada to use such technologies as in-vitro fertilization to select the sex of a fetus.

But an ultrasound can show the baby's sex at 14 weeks' gestation, at which point a woman can choose to terminate the pregnancy.

Urquia says because abortions are legal and covered by government health insurance, families with a preference for sons may be using the procedure to try to get a boy.

The study was published Monday in the Canadian Medical Association Journal.

You can read the full study here: