Just as Health Secretary Robert F. Kennedy Jr. has called for an investigation into debunked claims of vaccines causing autism, a massive new study bolsters a body of evidence behind an entirely different link to the neurodevelopmental disorder: gestational diabetes.
The study, out of China and published in the Lancet Diabetes & Endocrinology journal, is the latest to show a connection between diabetes during pregnancy, which affects up to 9% of U.S. pregnancies, and an increased risk not only of autism, but also other brain and nervous system problems.
Autism spectrum disorder (ASD) is a developmental disability caused by differences in the brain, according to the Centers for Disease Control and Prevention. While some people with ASD have a known difference, like a genetic condition, other causes are not yet known, and scientists believe there are multiple causes that act together.
While the research—a meta-analysis of data pooled from 202 earlier studies of more than 56 million mother-child pairs—doesn’t show whether gestational diabetes actually causes those problems, it shows that when mothers have diabetes while pregnant, children are 28% more likely to be diagnosed with a neurodevelopmental disorder.
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For autism, the risk was 25% higher for children of mothers with diabetes during pregnancy—and 30% higher for attention deficit hyperactivity disorder (ADHD), 32% higher for intellectual disability, 20% higher for trouble with communication, 17% higher for movement issues, and 16% higher for learning disorders—compared to babies whose mothers did not have gestational diabetes.
Further, the researchers noted, having diabetes diagnosed before pregnancy appears to be linked with a 39% higher risk for one or more of those neurodevelopmental disorders than having gestational diabetes, which often resolves with the birth.
Past research has also found a higher diabetes prevalence in people with autism, and also that people with autism may have a higher risk of developing diabetes. And a 2022 meta-analysis out of the U.K. found evidence of a statistically significant association between ASD and diabetes.
Researchers behind the latest analysis said that more research is needed, and called for “diligent monitoring” of blood sugar levels throughout pregnancy.