Autism is only a set of conditions and behaviors. What causes it is still unknown. It's been known even gut bacteria can interfere with neurological processes, so just because it is neurologocal does not mean the cause is only in the brain and nowhere else.  Very likely, like cancer, it has many causes, some just genetic bad luck, but also some behaviors a mother can do in order to increase the chances of it developing. Before AND after birth.  You were likely just a genetic case. Sperm and egg met, and that's that. Like some people are born with a highly increased chance of cancer and even get it as kids. But that doesn't mean that obeasts with diabetes getting pregnant aren't also acively causing it in their kids, like smokers cause their own tumors.