Thanks tejodouro - I do not know the details about my brother-in-law's autism except that he is high functioning. I will ask about it.
Any other information that helps me to ask a doctor the right questions is greatly appreciated.
Yes. Autism runs in some families. Do you know if your brother in law has autism caused by Fragile X (easy to test via a simple bloss test) ? If so, that type of autism (which is a minority of the cases) is passed to the child by the mother. If he has autism caused by fragile X but you yourself do not carry the fragile X chromosome, you probably will not have a child with autism. You need to see a genetic specialist. Do your research and go ask the questions.
My oldest child is autistic and we recently found out that my father has 2 cousins (not siblings) who are autistic.
Autism can be hereditary, so you are at greater risk for passing it down unfortunately. There are a few mental disorders in my family, Autism mostly. My brother has it.