For the first time, researchers have identified a link between maternal polycystic ovary syndrome and increased risk of autism for offspring.
Lead researcher Kyriaki Kosidou, of the Department of Public Health Sciences at Karolinska Institutet in Sweden, and colleagues publish their findings in the journal Molecular Psychiatry.
Autism - a developmental disability characterized by social, communication and behavioral problems - currently affects around 1 in 68 children in the US, increasing from 1 in 150 children in 2000.
While the exact causes of autism remain unclear, past studies have suggested that a child's exposure to specific sex hormones known as androgens in early life may influence development of the condition.
Despite both men and women producing androgens - such as testosterone and androstenedione - the hormones are often referred to as "male hormones," because they play a key role in male traits and men produce them at much higher levels. These hormones also contribute to brain development.
Androgen production is increased among women with polycystic ovary syndrome (PCOS) - a condition that affects the functioning of the ovaries. With this in mind, Kosidou and colleagues set out to investigate whether a PCOS diagnosis during pregnancy may influence autism development among offspring.
59% greater autism risk for children of mothers with PCOS
To reach their findings, the team used the Swedish health and population register databases to gather information on all children aged 4-17 years who were born in Sweden between 1984-2007.
The researchers identified 24,000 children with autism and compared them with 200,000 children without the condition.
- Autism is around five times more common in boys than girls
- Parents who have a child with autism have a 2-18% chance of having a second child with the disorder
- Around 46% of children with autism are identified as having an intellectual ability that is average or above average.
Compared with children born to mothers without PCOS, those born to mothers diagnosed with the condition during pregnancy were found to be at 59% greater risk of autism development.
The risk of autism was even higher for children born to mothers who had PCOS and were obese; such women tend to have significantly high androgen levels, according to the team.
While autism is much more common among boys than girls, the team says they identified no sex differences in autism risk among children born to mothers with PCOS.
The researchers were unable to identify the exact reasons for their findings, but they hypothesize that the association between maternal PCOS and increased autism risk may be driven by increased androgen levels.
It is also possible that autism and PCOS have shared genetic factors, according to the team, and the association may also be a result of other metabolic problems that arise among women with PCOS.
The researchers say further studies are needed to replicate their findings and to determine the underlying mechanisms.
Until then, senior study researcher Renee Gardner, also of the Department of Public Health Sciences at Karolinska, says it is too early to make clinical recommendations for pregnant women with PCOS, "though increased awareness of this relationship might facilitate earlier detection of ASD in children whose mothers have been diagnosed with PCOS."
Last month, Medical News Today reported on another study from Karolinska that claimed to shed light on how PCOS increases the risk for poor mental health.