Indians are known for their preference for male children, and according to a new study, some Indian-origin couples living in Canada -- mostly those from Punjab and the Hindi heartland -- may be practicing sex selective abortion out of a preference for boys.

Interestingly, the research published in the Journal of Obstetrics and Gynaecology Canada found that longer the women lived in Canada, the greater was the gender imbalance in live births. The practice of sex-selective abortion appeared to be more common among those who already had two daughters.

Canada has no legal restrictions on sex-determination tests and sex-selective abortion unless use of reproductive technology is involved. The study was done by the same group of researchers who reported last year that more male babies than expected were being born to Indian-born women living in Canada.

In their research published in 2016, the researchers found that women born in India, who already have two daughters, gave birth to 196 baby boys in Ontario for every 100 girls while in most of the world, between 103 and 107 boys are born for every 100 girls and Canadian-born women living in Canada give birth to about 105 boys for every 100 girls.

The new study revealed that the skewed ratio of male to female babies born to Indian-born women does not change with the length of time the women live in Canada, as the researchers would have expected it to. The findings suggest that the gender imbalance will not be corrected without interventions that include community involvement and education, said lead researcher Marcelo Urquia from St. Michael's Hospital in Toronto.

Noting that India is a culturally and linguistically diverse country, Urquia, who is also Assistant Professor at University of Manitoba, set out to see whether the practice was more common among some groups.

He looked at records relating to 46,834 live births to Indian-born women who immigrated to the province of Ontario between 1985 and 2012 and gave birth in Canada between 1993 and 2014.  Among all Indian-born women with two previous daughters, elevated male-to-female ratios were particularly evident among women whose mother tongue was Punjabi, findings of the latest study showed.

At their third delivery in Ontario, these women had 240 boys for every 100 girls. The researchers also examined whether this sex imbalance corrected itself after immigrants spent more time in Canada. 

Women whose mother tongue was Punjabi gave birth to 213 boys for every 100 girls if they had lived in Canada for less than 10 years. The number went up to 270 boys for every 100 girls if they had lived in Canada for more than 10 years -- the opposite of what researchers would have expected, Urquia said. 

Indian-born women whose mother tongue was Hindi gave birth to 163 boys for every 100 girls overall, 130 boys if they lived in Canada less than 10 years, and 217 boys if they lived in Canada for more than 10 years, the study said.