True, but the key metric is age at first pregnancy-to-term, not age at last. On that basis there has been a dramatic shift over the past century.
I fail to see the difference between a 40yr old egg and a 40yr old egg.
Unless there is some ‘protective’ effect of having been pregnant in the 20’s and 30’s. In which case the ‘genetic’ effect of autism isn’t strictly ‘genetic’. It’s somewhat environmental.