Perhaps in the future when we are all tested for inherited gene problems then Autism can be prevented through choice in which sexually active adults refrain from procreating.

There are already some countries were gene testing before marriage is compulsory:

Who owns your genes? ABC Australia, The Philosopher's Zone:

Justin Oakley:

In Cyprus now for almost 30 years it’s been compulsory for couples intending to marry to obtain a premarital genetic test for thalassaemia, because there’s a particularly high incidence of that genetic disease in Cyprus and it’s one that without treatment reduces your life expectancy to about five years of age for the child that’s born with it. So Cyprus, way back in 1982, they introduced this program whereby couples have to obtain a genetic test in order to get a marriage licence. It’s then up to the couple to decide what to do with that information. So the couple, if one of them finds that they’re a carrier for this particular disorder, then they can decide perhaps to test the foetus, if they become pregnant with it. Or indeed perhaps decide not to get married at all to the same partner.

Pregnant women are given more knowledge about the health of the fetus their are carrying and there must be opportunity for anyone not wishing to deliver a baby that has severe problems to abort. Knowledge is always empowering.