Many doctors and scientists were reeling Monday after President Donald Trump went on TV to insist that pregnant women should never take Tylenol and revive debunked theories about vaccines and autism. Dr. Steven Fleischman, president of the American College of Obstetricians and Gynecologists, worried that the Tylenol claims would terrify mothers-to-be and parents of children with autism. Here’s what we know about autism and the Trump administration’s new steps to address it. For some people, profound autism means being nonverbal and having intellectual disabilities, but the vast majority of people experience far milder effects. In the early 2000s, as the definition began changing, the autism rate was estimated to be 1 in 150 children.