What causes one to develop autism? is it something the child is born with? is their anything a pregnant woman can do to help prevent this?

Multiple factors: This is a very complex question, and a lot of research is under way to answer these very questions. Your obstetrician should be an excellent source of information for you. Currently, we believe that autism has several factors--genetic inheritance, development during pregnancy, infections, trauma, toxins present during pregnancy, and so on. Please get reputable guidance from your ob.

Mostly genetic: The strongest evidence is that genes comprise a much bigger part of the pie influencing this outcome. There is a variety of evidence that only weakly finds the environment causal e.g. diet and vaccines. But of course, being selective about wholesome foods and lifestyle preferences e.g. exercise, being aware of medications that are safe during pregnancy, and for the baby later on is top job.

Worrisome issue: To date multiple coding errors buried within the genes have been detected in many affected kids.That means the problem for them was in the egg or sperm prior to conception.The best any mom can do is follow a good diet,avoid exposures you know are a problem & get good prenatal care.It may be decades before we sort out the trigger or triggers to this problem.