A Swedish study involving 24,000 children with autism supports a long-held view that exposure to sex hormones early in life may be an important factor in the development of autism.
Led by scientists at Sweden’s Karolinska Institutet medical university, the research is the first to highlight the link between polycystic ovary syndrome (PCOS) and autism in children.
According to lead researcher Kyriaki Kosidou, the study indicated that PCOS increased the risk of ASD in an offspring by as much as 59 per cent.
The sex hormones under scrutiny are androgens, which are responsible for the development of male-typical characteristics. Androgens also affect the development of the brain and central nervous system.
Women with PCOS are said to have an increased level of androgens even during pregnancy, leading the research team to hypothesise that the disorder may affect the risk of ASD in their offspring.
PCOS is a common hormonal endocrine disorder. It has been known as a ‘silent killer’, putting women at risk of developing several serious medical conditions such as heart disease, type 2 diabetes, high blood pressure and high cholesterol.
Being both obese and having PCOS is thought to increase the risk. Kosidou said: “The risk was further increased among mothers with both PCOS and obesity, a condition common to PCOS.”
The 24,000 children with autism who took part in the study, published in the Journal of Molecular Psychiatry, were born in Sweden between 1984 and 2007. They were compared to 200,000 children without an autism diagnosis.
In addition to the increased exposure to maternal androgens, the researchers suggest that other possibilities for the PCOS/autism link may be a shared genetic influence between the two conditions.
Other metabolic problems common to PCOS might also partly explain the relationship between autism and sex hormones. The scientists are hoping to carry out more research.
Renee Gardner, senior investigator on the study, said it was too early to make specific recommendations to clinicians in terms of the care of pregnant women with PCOS.
She did, however, suggest that “increased awareness of this relationship might facilitate earlier detection of ASD in children whose mothers have been diagnosed with PCOS”.
Published: 10 December 2015
