What would be your advice about preventing autism? Does the age of the father matter?

If you have a child with autism would you recommend having additional children?
Other studies, than the one on the Israelis have shown that the biggest risk factor for autism is having it in the family and paternal age is only relevant when there is no family history of the spectrum.

What about prevention for the sake of the suffering that someone with autism must go through rather than what you might feel as the parent?