Topic 1: Environmental Factors

Environmental factors may also play a role in increasing a person's risk for ASD. According to the CDC and Autism Speaks, scientists generally agree that the time when environmental factors pose the most risk for ASD are right before, during, and right after a baby's birth. (This is the period that environmental factors have the most impact on a child's development overall – not just for ASD.) The CDC and the NIMH list the following as generally agreed-upon environmental factors that may increase the risk for ASD:

• Being born to parents of advanced maternal or paternal age. (This includes a mother who was 35 years of age or older and/or a father who was age 40 or older at the time of conception.)
• A mother who took the prescription drugs Valproic acid and Thalidomide while pregnant.

Autism Speaks also lists the following as environmental factors that may increase the risk of ASD:

• A mother's illness during her pregnancy
• Very premature birth
• Low birth weight
• A mother's exposure to high levels of air pollution or pesticides during her pregnancy

It is generally agreed that these factors do not guarantee that a child will have ASD, only that they MAY increase a child's risk for ASD.

This video of a TEDTalk by Wendy Chung, a geneticist, provides an overview of what we know about the genetic and environmental causes of autism, and what we still need to learn. Dr. Chung is the director of clinical research at the Simons Foundation Autism Research Initiative and the director of the clinical genetics program at Columbia University. Dr. Chung's research focuses on finding the genetic basis for neurological conditions, including autism and other intellectual disabilities.

Here is the link to the transcript: Wendy Chung: Autism - what we know (and what we don't know yet) Video Transcript