Autism Linked to Elevated Levels of Steroid Hormones in the Womb

It turns out that steroids may have more to do with autism development than scientists once thought. Researchers have found that children who later develop autism are exposed to elevated levels of steroid hormones, such as testosterone, progesterone and cortisol, while still in the womb.

In order to learn a little bit more about how children with autism might develop differently in the womb, the researchers analyzed about 19,500 amniotic fluid samples from individuals born between 1993 and 1999. These samples were collected at a critical time for early brain development and sexual differentiation in the children; this, in particular, allowed the scientists to get an inside look when it came to fetal development. Then, the researchers identified fluid samples from 128 males who later developed an autism spectrum condition.

The researchers looked at four key "sex steroid" hormones in the amniotic fluid. In the end, they found that the levels of all of these hormones were highly associated with each other and that on average, the group with autism had higher levels of these hormones when compared to the typically developing group.

"This is one of the earliest non-genetic biomarkers that has been identified in children who go on to develop autism," said Simon Baron-Cohen, one of the researchers, in a news release. "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."

The findings have important implications for what might cause autism and what factors in development might play a role. This could lead to future treatments or simply a better understanding of how to detect autism early in children.

The findings are published in the journal Molecular Psychiatry.