Older mothers and those who experience problems during pregnancy may be more likely to give birth to a child with autism, according to an analysis of several studies published in the July issue of the British Journal of Psychiatry.

After looking at 40 studies, researchers found that the risk of having a child with autism appears to increase dramatically with the mother’s age. Women ages 30 to 34 are 27 percent more likely than younger mothers to have a child with the disorder while women over 40 are 100 percent more likely to give birth to a child with autism compared to a mother under age 30.

A father’s age is also a factor, with the chance of autism rising 4 percent for every five years.

Researchers also found an increased risk of autism among women who experienced gestational diabetes and in pregnancy bleeding. Further, mothers who took medication, particularly psychiatric, during pregnancy were also at greater risk.

The researchers note that future studies should include DNA collection to better understand the genetic and environmental factors at play, reports the BBC. To read more click here.