The latest research into causal factors of autism, specifically in the case of boys, reveals the disorder may be tied to high levels male hormones while a fetus is in the womb, according to a new University of Cambridge report.

Researchers say the study indicates that high levels of male hormones does affect both sexes while in fetal development but appears to impact male boys the most. That may be, however, because the hormones are created in a higher quantity in a male fetus.

Testosterone and three additional steroid hormones that play a critical role in fetal development cannot be stemmed or blocked, according to a report published in Molecular Psychiatry.

"This is one of the earliest non-genetic biomarkers that has been identified in children who go on to develop autism. We previously knew that elevated prenatal testosterone is associated with slower social and language development, better attention to detail, and more autistic traits. Now, for the first time, we have also shown that these steroid hormones are elevated in children clinically diagnosed with autism," states study author Professor Simon Baron-Cohen.

The researchers examined the amniotic fluid of two groups of boys in fetal development and later then tested the children for levels of hormones. In the boys who developed autistm the steroid hormone in the amniotic fluid was high compared to the boys without autism.

"Because some of these hormones are produced in much higher quantities in males than in females, this may help us explain why autism is more common in males," said Baron-Cohen.

While the study participants did involve females the authors say more investigation is required to see if there is a hormone and autism relation.

"Despite a growing awareness of the biological and genetic nature of autism, there is currently no agreed biological or genetic marker for autism, with diagnosis made on the basis of early developmental history and behavioral criteria. So research that sheds light on this specific area is critical to our understanding of this mysterious and highly complex group of conditions," said Richard Mills, of Research Autism

Boys are four to five more likely to be diagnosed with an autistic spectrum disorder.