The characteristic behaviors of autism spectrum disorders may or may not be apparent in infancy (18 to 24 months), but usually become obvious during early childhood (24 months to 6 years).
As part of a well-baby/well-child visit, your child's doctor should do a "developmental screening," asking specific questions about your baby's progress. The National Institute of Child Health and Human Development (NICHD) lists five behaviors that signal further evaluation is warranted:
Having any of these five "red flags" does not mean your child has autism. But because the symptoms of the disorder vary so much, a child showing these behaviors should have further evaluations by a multidisciplinary team. This team may include a neurologist, psychologist, developmental pediatrician, speech/language therapist, learning consultant, or other professionals knowledgeable about autism.