CAMBRIDGE, England — Around 20 years ago, it was first proposed that prenatal hormones may play a part in the development of autism. Now, new research out of the University of Cambridge has found a link between high levels of estrogen in the womb and the likelihood of a child developing autism.
This new study builds off of previous research conducted in 2015 at the University of Cambridge and the State Serum Institute in Denmark. Four years ago, the same team of researchers measured the levels of four prenatal steroid hormones, including two known as androgens, in 275 amniotic womb fluid samples. Androgens are hormones that regulate the development of male characteristics.
All four steroid hormones were found to be present in larger quantities among male fetuses who would go on to develop autism. Since these hormones, especially the androgens, are produced in larger amounts in boys, the researchers at the time theorized that they may have found an explanation as to why autism occurs more frequently in males.
For the new study, researchers used the same amniotic fluid samples, except this time they measured four estrogen-based hormones. Among the 98 studied fetuses who developed autism, all four estrogen hormones were significantly higher compared to the 177 fetuses who did not develop autism.
Despite the researchers previous theories that male centric hormones may be causing autism, higher levels of prenatal estrogen hormones were found to be even more predictive of an autism diagnosis than high levels of masculine androgens, such as testosterone. It’s worth mentioning that despite the general belief that estrogen only works to foster feminine traits, it is also involved in brain growth and masculization in numerous mammals.
“This new finding supports the idea that increased prenatal sex steroid hormones are one of the potential causes for the condition. Genetics is well established as another, and these hormones likely interact with genetic factors to affect the developing foetal brain,” comments Professor Simon Baron-Cohen in a release.
Researchers say they aren’t sure exactly where these increased hormone levels are coming from just yet, and want to perform additional research to determine if they are being produced from the mother, the child, or the placenta.
“This finding is exciting because the role of oestrogens in autism has hardly been studied, and we hope that we can learn more about how they contribute to foetal brain development in further experiments. We still need to see whether the same result holds true in autistic females,” explains Dr Alexa Pohl.
However, the researchers say that while their findings are interesting and promising, their endgame is not to develop a method of autism screening or prevention. “We are interested in understanding autism, not preventing it,” Professor Baron-Cohen adds.