Are Gestational Diabetes and Autism Linked?

In a groundbreaking study involving over nine million pregnancies, researchers have revealed that children born to mothers with gestational diabetes face greater risks of developing attention deficit–hyperactivity disorder (ADHD) and autism. This significant research, presented at the European Association for the Study of Diabetes in Vienna, has garnered attention for its sheer scale, pooling results from 48 studies across 20 countries.

The findings show children of mothers with gestational diabetes scored lower on IQ tests and were found to have a 36% increased risk of ADHD and a staggering 56% higher risk for autism spectrum disorders. Given that the general prevalence of autism is about one in every 127 individuals and 3-10% of children and teens have ADHD, these numbers raise vital questions.

Previous Studies Support New Findings

Interestingly, this is not the first study to link gestational diabetes with neurodevelopmental disorders, but it stands out due to its large sample size. Back in June, another analysis published in The Lancet Diabetes & Endocrinology also indicated that any form of diabetes during pregnancy—type 1, type 2, or gestational—increased the likelihood of babies developing ADHD and autism. However, crucially, no definitive evidence has yet emerged to establish that diabetes causes these conditions.

"There's no doubt that there is a signal here, but further research is crucial," notes Alex Polyakov, an obstetrician and researcher at the University of Melbourne.

The Autism Debate Heats Up

Autism has been a hot-button topic, particularly with recent comments from former President Donald Trump regarding a supposed link between autism and the use of acetaminophen (paracetamol) during pregnancy. Despite medical guidelines deeming acetaminophen safe for pregnant women, the ongoing debate on autism's origins remains contentious.

The Bigger Picture: Genetics vs. Environment

It's essential to note that genetics plays a significant role in the development of ADHD and autism, with environmental factors such as folic acid deficiency, pollution, and gestational diabetes having a smaller yet impactful role. Ling-Jun Li, a clinician-scientist at the National University of Singapore and co-author of the recent study, emphasizes that genetic predispositions and environmental variables likely interact in complex ways.

Health Implications of Gestational Diabetes

The health implications of gestational diabetes extend beyond the immediate risk to children; studies from the past two decades have shown long-term effects on women, such as elevated risks for type 2 diabetes, heart disease, and chronic kidney disease.

Li and her team reviewed various studies, most of which linked gestational diabetes to increased instances of ADHD and autism, while others showed no correlation—mainly due to small sample sizes that limited their power to detect potential effects.

What Factors Could Contribute?

Polyakov provides insight that factors beyond gestational diabetes could influence neurodevelopmental risk, including higher obesity rates, smoking, and socioeconomic status among those who develop the condition during pregnancy.

Last year, an expansive study involving 3.6 million mother-child pairs indicated that any type of diabetes during pregnancy also slightly increased ADHD risks, but interestingly found that siblings had similar ADHD risks regardless of whether their mother had gestational diabetes.

The Path Forward: Further Research Required

Moving forward, Polyakov suggests future research focus on comparing the impacts of mild versus severe gestational diabetes on developmental risks, which may provide more clarity on whether gestational diabetes influences children's neurodevelopment.