New research from the Autism Research Centre and the Rosie Hospital, both at the University of Cambridge, suggests that maternal steroid factors during pregnancy are associated with autistic traits in mothers and their infants.
Previous studies have shown a relationship between prenatal sex steroid hormones and the likelihood of autism in the children, as well as with the amount of autistic traits and developmental profiles in the general population. In addition, autistic females were found to have brain structures that are more similar to males than undiagnosed females, as well as more symptoms relating to steroids throughout life. Autistic boys and girls also seem to have more male-like facial features than their undiagnosed peers. These findings together suggest a general "male shift" which is likely to be regulated by sex steroid hormones during early development. Large epidemiological studies have also consistently shown higher likelihood of autism in the children of women with polycystic ovary syndrome (PCOS); a condition that is often characterised by elevated sex steroid hormones. However, the complex interactions between family history, the sex of the child and the various different hormones in the prenatal environment (e.g. testosterone or estrogens) are not yet fully understood.
This research is the first clinical longitudinal study to report on the endocrine profile of pregnant women and how this relates to their own autistic traits, as well as the autistic traits of their infants. A team of researchers including Professor Simon Baron-Cohen and Dr Alex Tsompanidis collected serum samples from 122 pregnant women and measured concentrations of a number of sex steroid hormones, as well as the free fractions of estradiol (FEI) and testosterone (FTI). The mothers completed the standard Autism Spectrum Quotient (AQ) and, when their infants were between 18 and 20 months old, the Quantitative Checklist for Autism in Toddlers (Q-CHAT). They also reported whether they had a history of hirsutism (excess body hair) or PCOS, both conditions that are caused by excess androgens (steroids such as testosterone) in women.
The researchers found that mothers with a family history of autism and mothers who reported a history of hirsutism both scored significantly higher on the AQ tests than women without these factors. They also found that the autistic traits of the mothers correlated to the autistic traits of their infants, independently of family history for the condition. Finally, they found that levels of estradiol were positively correlated with AQ scores in the mother and the Q-CHAT scores in their male children. This is the first study to show a positive correlation between the autistic traits of the mother and infant, as well as between the levels of the same maternal hormones and the autistic traits of both. Together, these findings support the theory that autistic traits in the children are associated with maternal steroid factors.
These links will be further explored in the future, by Professor Baron-Cohen and Dr Tsompanidis, who will collaborate with the Centre for Trophoblast Research to study the role of the placenta in neurodevelopment and the health of autistic people.
You can read the full article here
Image credit: Gabe Pierce on Unsplash