Currently, there are no prenatal tests available for autism. Some experts say such tests are currently being developed, but my skeptical mind really wonders what exactly they would test for. After all, the cause of autism is still unclear, and the condition can take many different shapes and forms people with autism range from those for whom human interaction is a huge challenge, to highly intelligent Asperger Syndrome people. The Autism Spectrum Disorders are indeed a huge spectrum. The view that autism can (at least in some cases) be caused by external factors that take place after birth make the accuracy of a prenatal test even more questionable.
I spent some time reading autism advocacy websites, created by people with autism and parents of children with autism. It was quite eye-opening. Autism advocates argue that any future prenatal test for the condition would serve no purpose other than to facilitate abortion for those unborn babies who are found to have autism. Babies with autism do not require any special prenatal or newborn care. I'm sure the debate will continue if and when a prenatal test for autism becomes available. In the meantime, it might be better to focus autism research on the causes of the condition!