Mothers who took antidepressants during pregnancy may be putting their children at risk of autism, a new study suggests.

Researchers at the University of Bristol found that the children of women who took pills in pregnancy were 41 per cent more likely to be autistic.

However the absolute risk is still small, rising from 2.9 in 100 children to 4.1.

Up to eight per cent of pregnant women are prescribed antidepressants during their pregnancy in Britain, and there are around 700,000 births a year.

Researchers analysed data from 254,610 individuals aged 4-17, including 5,378 with autism, living in Stockholm in 2001-11.