Diabetes linked to cognitive decline in mothers and neurodevelopmental risks in children

Gestational diabetes is tied to cognitive decline in mothers and higher risks of autism and ADHD in children, according to new research.

The ongoing systematic review and meta-analysis covered 48 observational studies involving more than 9m pregnancies across 20 countries, with data included up to April 2024.

It found clear cognitive impacts for both mothers and children.

Researchers at the National University of Singapore reported that mothers with gestational diabetes scored 2.47 points lower on cognitive assessments than those without the condition.

Gestational diabetes is high blood sugar that develops during pregnancy, affecting about 14 per cent of pregnancies worldwide.

Children born to affected mothers scored an average of 3.92 points lower on IQ tests and had a 3.18 point reduction in verbal crystallised intelligence – the ability to understand, analyse and communicate effectively through language.

The analysis also showed children faced a 45 per cent higher risk of developmental delay, a 36 per cent greater likelihood of attention-deficit/hyperactivity disorder (ADHD), and a 56 per cent higher risk of autism spectrum disorder (ASD).

Dr Ling-Jun Li from the School of Medicine, National University of Singapore, said: “There are increasing concerns about the neurotoxic effects of gestational diabetes on the developing brain.

“Our findings underscore the urgency of addressing this significant public health concern that poses substantial cognitive dysfunction risks for both mothers and offspring.”

The condition usually resolves after birth but can still cause complications.

Mothers face higher risks of high blood pressure and caesarean delivery, while children have increased risks of premature birth, large birth weight and neonatal hypoglycaemia (low blood sugar in newborns). Children are also more likely to develop obesity and diabetes in adulthood.

Women who are obese, older mothers, those from non-white backgrounds and those with a family history of diabetes are at greater risk of developing it.

Although the exact mechanisms remain unclear, researchers suggest factors such as inflammation, stress in cells, reduced oxygen supply and high insulin levels may affect the baby’s brain development in the womb.

The Montreal Cognitive Assessment used in the study tests functions such as memory, attention and problem-solving, with a maximum score of 30.

The meta-analysis found no major differences in overall brain structure or general cognitive scores between affected and unaffected children.

Presenting author Caitlin Por, a medical student at Monash University in Melbourne, Australia, said: “Longer follow-ups across childhood are also needed to examine whether these associations persist or progress further to other worse outcomes.”

The authors stressed the need for early screening and careful management to limit neurocognitive complications in mothers and children.

Further research is needed to establish causality and clarify the links between gestational diabetes and the full range of cognitive outcomes.