Statistical distributions suck, especially when we want a clear-cut cause-and-effect silver bullet. My only sister has two autistic sons, and my wife and I were 7 years older than she was when we had our son and he isn't autistic (as far as we can tell thus far).

As a brother and uncle, I have incredible empathy for the desire and frustration to just get a clear answer on this. And I recognize these feeling however intense are orders of magnitude less than for a parent. It's not like lead or asbestos or thaledimide or radiation.

Best we've got is a confluence of factors, not the least being family history knowing full well how bad diagnosis has been historically.

It's so incredibly predatory to dump the science in the trash and just say "it was Tylenol all along".