CLICK ON weeks 0 - 40 and follow along every 2 weeks of fetal development
Developmental biology - Autism|
Moms with PCOS more likely to have child with autism
PCOS affects about one in ten women and is caused by elevated levels of the hormone testosterone. It is associated with fluid-filled sacs (called follicles) in the ovaries, and with symptoms such as delayed onset of puberty, irregular menstrual cycles, and excess bodily hair.
Autism is a condition characterized by difficulties with social interaction and communication alongside unusually narrow interests, reflecting a strong preference for predictability, which leads to difficulties adjusting to unexpected change. Some autistic people may also have learning difficulties with delayed language, many have hyper-sensitivity to sensory inputs. The signs of autism are evident in childhood even if diagnosis is not made until much later, and occurs in about 1% of our population.
Researchers previously published work in 2015 showing that before birth, autistic children have elevated levels of 'sex steroid' hormones (including testosterone) which 'masculinise' the baby's body and brain. A discovery of prenatal sex steroid hormones in the development of autism could be a possible explanation for why autism is diagnosed more often in boys.
The team wondered where elevated sex steroid hormones were coming from, with one possible source being mothers with higher than usual levels of testosterone, as is women with PCOS. Some of the hormone might cross the placental barrier in pregnancy, exposing her unborn baby to more of the hormone and changing her baby's brain development.
Using anonymous data from a large database of GP health records, the study looked at 8,588 women with PCOS and their first-born children, as compared to a group of 41,127 women without PCOS.
The team found taking into account factors such as maternal mental health problems or complications in pregnancy, women with PCOS had a 2.3% chance of having an autistic child, compared to a 1.7% chance in mothers without PCOS.
The team stresses that the likelihood of having an autistic child is still very low, even among women with PCOS - but finding this link provides an important clue in understanding one of the multiple causal factors in autism.
Presenting their findings at the International Meeting for Autism Research in 2016, their work was replicated by a Swedish study that same year, adding to the reliability of their findings.
Conducting two other studies using the same data, researchers found that autistic women were more likely to have PCOS, and women with PCOS were more likely to have autism themselves. This strongly suggests that these two conditions are linked, probably because they both share elevated sex steroid hormone levels.
According to Professor Simon Baron-Cohen, Director of the Autism Research Centre, who supervised the research: "This new research is helping us understand the effects of testosterone on the developing fetal brain, and on the child's later behaviour and mind. These hormonal effects are not necessarily independent of genetic factors, as a mother or her baby may have higher levels of the hormone for genetic reasons, and testosterone can affect how genes function."
Elevated levels of prenatal testosterone may increase the risk for autism spectrum conditions (autism). Given that polycystic ovary syndrome (PCOS) is also associated with elevated prenatal testosterone and its precursor sex steroids, a hypothesis from the prenatal sex steroid theory is that women with PCOS should have elevated autistic traits and a higher rate of autism among their children. Using electronic health records obtained from the Clinical Practice Research Datalink (CPRD) in the UK between 1990 and 2014, we conducted three matched case-control studies. Studies 1 and 2 examined the risk of PCOS in women with autism (n = 971) and the risk of autism in women with PCOS (n = 26,263), respectively, compared with matched controls. Study 3 examined the odds ratio (OR) of autism in first-born children of women with PCOS (n = 8588), matched to 41,127 controls. In Studies 1 and 2 we found increased prevalence of PCOS in women with autism (2.3% vs. 1.1%; unadjusted OR: 2.01, 95% CI: 1.22–3.30) and elevated rates of autism in women with PCOS (0.17% vs. 0.09%, unadjusted OR: 1.94 CI: 1.37–2.76). In Study 3 we found the odds of having a child with autism were significantly increased, even after adjustment for maternal psychiatric diagnoses, obstetric complications, and maternal metabolic conditions (unadjusted OR: 1.60, 95% CI: 1.28–2.00; adjusted OR: 1.35, 95% CI: 1.06–1.73). These studies provide further evidence that women with PCOS and their children have a greater risk of autism.
Authors: Adriana Cherskov, Alexa Pohl, Carrie Allison, Heping Zhang, Rupert A. Payne and Simon Baron-Cohen.
The study was supported by the Autism Research Trust, the Medical Research Council, the Wellcome Trust, a Gates Cambridge Trust Scholarship and Rouse Ball/Eddington Research Fund Award at Trinity College.
Return to top of page
Signs and symptoms of PCOS often develop around the time of the first menstrual period during puberty. Sometimes PCOS develops later, for example, in response to substantial weight gain.
Image Credit: Mayo Clinic