(A girl stands on posters during a rally against abortion in the southern Indian city of Hyderabad October 2, 2008/Krishnendu Halder)

Up to 12 million girls were aborted over the last three decades in India by parents that tended to be richer and more educated, a large study in India found, and researchers warned that the figure could rise with falling fertility rates.

The missing daughters occurred mostly in families which already had a first born daughter. Although the preference for boys runs across Indian society, the abortions were more likely to be carried out by educated parents who were aware of ultrasound technology and who could afford abortions.

“The number of girls being aborted is increasing and may have reached 12 million with the lower estimate of 4 million over the last three decades,” said lead author Professor Prabhat Jha at the Center for Global Health Research in Toronto, Canada.

Jha said the preference for boys in Indian society remains firmly in place and the reason why abortions of female fetuses were occurring more among richer and educated parents was because they could afford to do so. “The preference for boys doesn’t differ between rich and poor, it is similar. But the means to ensure a boy is greater among the educated and the rich,” Jha said.