A new synthesis of global evidence finds that experiencing gestational diabetes during pregnancy is linked with a decline in intellectual function among mothers, and may increase the risk of neurodevelopmental disorders, including autism spectrum disorder and attention-deficit/hyperactivity disorder (ADHD) in children.
The ongoing systematic review and meta-analysis of 48 observational studies involving over 9 million pregnancies, is being presented at this year's Annual Meeting of The European Association for the Study of Diabetes (EASD), Vienna (15-19 Sept).
The authors say that given the increasing prevalence of gestational diabetes in pregnancies, the findings underscore the importance of accurate management and early screening to reduce and detect such neurocognitive complications for both mothers during pregnancy and children after birth.
"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," explains lead senior author Assistant Professor Dr Ling-Jun Li from the School of Medicine, National University of Singapore, Singapore.
Gestational diabetes, a type of diabetes that can develop during pregnancy, affects around 14% of pregnancies globally [1], and is becoming more common, with those who are living with obesity, have a family history of diabetes, non-White mothers, and those who are older at greater risk.
Gestational diabetes usually resolves after birth but can cause complications during and after pregnancy. Mothers, for example, are at increased risk of high blood pressure and primary caesarean delivery, and their children are at higher risk of premature birth, being born with a large-for-gestational-age weight, and having neonatal hypoglycaemia. Children are also more likely to develop obesity and diabetes in adulthood.
Additionally, a growing body of evidence indicates that gestational diabetes affects neurocognitive function in offspring. However, until now, there has been no comprehensive synthesis of the available evidence.
To find out more, researchers conducted a systematic review and meta-analysis, combining the results of observational studies up to April 2024 examining the impact of gestational diabetes on neurocognitive outcomes in both mothers antenatally and offspring (from birth to 29 years of age). Data were analysed for 48 studies involving over 9 million pregnancies from 20 countries and globally.
The analysis of five studies on maternal antenatal cognitive function found that mothers with a history of gestational diabetes scored significantly lower (by an average of 2.47 points) on the Montreal Cognitive Assessment (total score out of 30) compared to those without the condition.
Further analyses of 43 studies examining offspring cognitive function also found statistically significant disparities between children of pregnancies complicated by gestational diabetes and their counterparts. For example, children born to mothers with gestational diabetes had subsequent IQ scores 3.92 points lower than children not exposed to the condition, as well as a 3.18 point reduction in verbal crystallised intelligence (the ability to understand, analyse, and communicate effectively through language).
Additionally, children born to mothers who experienced gestational diabetes faced a 45% higher risk for total and partial developmental delays, were 36% more likely to have attention-deficit/hyperactivity disorder (ADHD) ), and were at a 56% increased risk for autism spectrum disorder (ASD).
However, no significant differences were found in major brain structure or general cognitive scores [2] between children born to mothers with gestational diabetes and those who were not in the meta-analysis.
The authors note that it is still not fully clear how gestational diabetes affects a child's brain development. However, several possible explanations exist. During pregnancy, factors such as inflammation, stress in the body's cells, reduced oxygen supply, and high insulin levels may influence how the baby's brain develops in the womb, which could later affect learning and cognitive abilities as the child grows.
The research team say that more research is needed to establish causality and clarify the associations between gestational diabetes and the full spectrum of cognitive functions. "Longer follow-ups across childhood are also needed to examine whether these associations persist or progress further to other worse outcomes," says the presenting author, Ms Caitlin Por, a Medical Student at Monash University, Melbourne, Australia.
