Researchers from the University of Cambridge have found that exposure to high levels of testosterone and other steroid hormones in the womb increases the chance of a baby boy being born with autism.
In an attempt to identify the cause of the condition – which is characterised by communication difficulties and is far more common in boys than girls – scientists conducted a study of over 300 boys and published their results in the journal of Molecular Psychiatry.
Lead researchers, Dr Michael Lombardo and Prof Simon Baron-Cohen, analysed stored samples of amniotic fluid – the liquid that cushions the baby when it is in the womb – to spot any signs that this early environment is linked to the development of autism.
It was discovered that for 128 boys who were later diagnosed with autism, levels of steroid hormone in their amniotic fluid were, on average, quite high. For the 217 boys without autism however, tests showed far lower levels of steroid hormones present in their amniotic fluid.
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.”
Although the findings pinpoint an important discovery in foetal development and how autism might be triggered, University of Cambridge researchers stress the study is unlikely to lead on to a prenatal test for autism.
Nor will the findings make it possible to stop autism by blocking these hormones – especially as the ones in question are important for foetal development, and blocking them could cause complications.