Children born to mothers with polycystic ovary syndrome (PCOS) face a higher risk of autism spectrum disorder (ASD), according to a large epidemiological study led by researchers at Sweden’s Karolinska Institutet. Published in the journal Molecular Psychiatry, the study strengthens evidence that prenatal exposure to sex hormones may influence autism risk in children of both sexes.
This population-based study is the first large-scale report linking maternal PCOS to increased odds of ASD in offspring. Autism spectrum disorders are neurodevelopmental conditions marked by challenges in social interaction and communication, along with restricted or repetitive behaviors. While ASD has multiple contributing factors, growing evidence suggests that early exposure to certain sex hormones—particularly androgens, which drive development of male-typical characteristics—may affect brain development and contribute to ASD risk.
Women with PCOS commonly have elevated androgen levels, including during pregnancy. Because androgens influence the developing brain and central nervous system, the researchers hypothesized that maternal PCOS could alter the likelihood of ASD in children. PCOS affects an estimated 5–15% of women of reproductive age, making it one of the most prevalent endocrine conditions in that population.
The team used Sweden’s comprehensive national health and population registers to conduct a matched case–control study of all children aged 4–17 born in Sweden between 1984 and 2007. In an anonymized dataset, they identified approximately 23,748 ASD cases and compared them with 208,796 matched controls. Matches were based on birth month and year, sex, and region of birth. Maternal PCOS and offspring ASD were defined using diagnostic codes recorded in healthcare registers.
After adjusting for potential confounders, the investigators found that a maternal diagnosis of PCOS was associated with a 59% increase in the odds of ASD in the child (odds ratio 1.59, 95% confidence interval 1.34–1.88). The association was stronger among mothers who had both PCOS and obesity, a combination linked to more pronounced hyperandrogenism; in this group the odds of offspring ASD were higher (odds ratio 2.13, 95% confidence interval 1.46–3.10). Importantly, risk estimates did not differ between boys and girls in this analysis.
The study did not investigate biological mechanisms directly. Besides increased prenatal androgen exposure, possible explanations for the observed association include shared genetic predispositions between PCOS and ASD or metabolic disturbances commonly associated with PCOS. Because this research is observational, it cannot prove causation; further studies are needed to replicate the finding and to explore underlying pathways, including the role of sex steroids and metabolic factors in ASD development.
Lead researcher Kyriaki Kosidou of the Department of Public Health Sciences emphasizes the significance of the association: “We found that a maternal diagnosis of PCOS increased the risk of ASD in the offspring by 59 percent.” Co-investigator Renee Gardner adds that while it is premature to change clinical management based on these results alone, increased awareness among clinicians may support earlier monitoring and detection of ASD in children born to women diagnosed with PCOS.
Several investigators are also affiliated with the Stockholm County Council Centre for Epidemiology and Community Medicine. The work received funding from Autism Speaks, the Stiftelsen Sunnerdahls Handikappfond Foundation, the Swedish regional agreement on medical training and clinical research (ALF), and the Swedish Research Council.
Source: Press Office – Karolinska Institutet
Image Credit: The image is in the public domain
Original Research: Full open access research: “Maternal polycystic ovary syndrome and the risk of autism spectrum disorders in the offspring: a population-based nationwide study in Sweden” by Kyriaki Kosidou, Christina Dalman, Linnea Widman, Stefan Arver, Brian K. Lee, Cecilia Magnusson, and Renee M. Gardner in Molecular Psychiatry. Published online December 8, 2015. doi:10.1038/MP.2015.183
Abstract (summarized)
This nationwide, population-based matched case–control study evaluated whether maternal polycystic ovary syndrome is associated with increased risk of autism spectrum disorders in offspring. The study included 23,748 ASD cases and 208,796 matched controls, born in Sweden between 1984 and 2007. Maternal PCOS was identified via diagnostic codes in health registers. After adjusting for confounders, maternal PCOS was associated with 59% greater odds of offspring ASD. The association was stronger when maternal obesity co-occurred with PCOS. No differences in risk between male and female offspring were detected. These findings suggest a potential role for maternal endocrine and metabolic factors in ASD etiology and highlight the need for replication and mechanistic research.