New research – claims that exposure to high levels of “male” hormones in the womb can increase the chance of a baby boy developing autism. The study adds to earlier research indicating that autism is linked to prenatal developments.
Researchers at the University of Cambridge and Statens Serum Institute in Copenhagen used Danish medical records in samples of 19,500 amniotic-fluid identified of boys born between 1993 and 1999. 128 boys who later went on to develop autism had on average higher levels of steroid hormone in their amniotic fluid.
Testosterone and three other steroid hormones are important for fetal development.
The study authors, Dr Michael Lombardo and Prof Simon Baron-Cohen, looked at stored samples taken from amniotic fluid to see if there was anything about this environment that might explain autism risk.
Lower levels of steroid hormone were found in the amniotic fluid of a control group of 217 boys without autism. Lead researcher Prof Baron-Cohen said:
“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.
“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.”
Prof Baron-Cohen noted that the findings are important because the results were found across the autism spectrum, including Asperger Syndrome. He said
“”The value of the new results lies in identifying key biological mechanisms during fetal development that could play important roles in atypical brain development in autism.”
The original study was published in Molecular Psychiatry yesterday.