Risk of autistic characteristics in children was more pronounced with those babies who were exposed to high levels of the male hormone testosterone in the womb, a recent study has revealed.
Researchers from Cambridge University recorded foetal testosterone levels in the amniotic fluid of 235 pregnant women.
They compared results against questionnaires designed to measure children's autistic traits between the ages of six and 10.
They found that high testosterone levels were linked to answers that reflected poor social skills, imagination and empathy but good attention to and memory for detail.
Professor Simon Baron-Cohen said the research went further than previous studies that had found links between foetal testosterone and less eye contact as a baby, slower language development and more difficulties with empathy.
''The study highlights for the first time the association between foetal testosterone and autistic traits, and indicates that foetal testosterone not only masculinises the body, it masculinises the mind,'' he said.
But he underlined that the study was not confirming a link between foetal testosterone levels and full-blown autism.
''We all have some autistic traits these are a spectrum or a dimension of individual differences, like height.
''It is important to note that this research does not demonstrate that elevated foetal testosterone is associated with a clinical diagnosis of autism or Asperger Syndrome,'' he added.
The Guardian newspaper said that the research, published in The British Journal of Psychology, could bring prenatal screening for autism closer to reality, potentially allowing women to terminate babies with the condition.
Baron-Cohen said this needed to be debated. ''If there was a prenatal test for autism, would this be desirable? What would we lose if children with autistic spectrum disorder were eliminated from the population?'' he said.
''We should start debating this. There is a test for Down's Syndrome and that is legal and parents exercise their right to choose termination, but autism is often linked with talent. It is a different kind of condition.''
Research could open the way for new treatments for autism, he said. But he acknowledged that this too would be controversial.
''We could do something about it. Some researchers or drug companies might see this as an opportunity to develop a pre-natal treatment. There are drugs that block testosterone.
''But whether we'd want to would be a different matter,'' he said.