According to a new study, it is not just the age of the mother, but also the age of the father than contributes to autism risk.
As older mothers are more likely to have babies with autism, so also are older fathers likely to contribute to the risk, even in those cases where the mothers may be under 30 years of age.
Though earlier research was able to demonstrate that risk of autism grew proportionately with the age of the father, the new research seems to show that when the father was over 40 and the mother under 30, the increased risk was especially pronounced — 59 percent greater than for younger men. The risk of a 40 year old woman having an autistic child is 50% higher than a woman in her late 20’s and 77% higher than women under age 25.
A seven fold rise in autism was noted in the 1990’s however not all can be said to be due to women becoming mothers in their 40’s. Paternal age was also therefore concluded to be a factor.