Birth experience vs Autism

Do you think there is a correlation with autism and age? People are having children later in life. I was 35 wife was 28 with first. Second I was 37 wife was 30.

I also wonder if more severe autism is associated with lack of oxygen at birth. Mamma and daughter had a traumatic birth experience. My wife has spoken with many parents and about 80% have had an issue with oxygen at birth.

Thoughts?