Gestational diabetes linked to higher autism risk; calls for earlier screening and lifestyle changes

Gestational diabetes is linked to a markedly higher risk of autism in children, according to a landmark review of nearly nine million pregnancies. The study, presented at a major diabetes conference, found that women who developed gestational diabetes were almost 60 percent more likely to have a child diagnosed with autism. It also noted a 36 percent higher likelihood of a child diagnosed with attention deficit hyperactivity disorder and an increased risk of foetal macrosomia, or a very large baby. The condition affects about one in 20 pregnant women.

A synthesis of data from 48 studies including more than nine million pregnancies concluded that while there is a robust association with autism, there is no single cause and genetics and environment both play a role. Experts cautioned against blaming mothers, noting that autism arises from a complex mix of factors and that the findings point to a preventable, lifestyle related factor rather than a simple cause. In the broader autism debate, researchers emphasized there is no proven paracetamol autism link and noted that the study does not single out any drug as the cause; the risk appears to be tied to the diabetes condition itself when present in pregnancy.

Yet many cases go undiagnosed in Britain. The NHS currently tests only a subset of pregnant women for gestational diabetes, typically offering an oral glucose tolerance test at about 24 and 28 weeks to those judged at risk. Some experts argue that testing should be offered earlier in pregnancy, particularly when a baby appears larger on scans, but resources do not always allow it. The test itself can be unreliable, with some cases missed by the two hour threshold; clinicians say testing after one hour could reduce missed diagnoses.

Estella Newbold-Brown, a 43 year old from south London, describes how she felt she was healthy during pregnancy and then was unsure about a diagnosis around the time of delivery. A 24 week test showed no sign of diabetes, but later tests revealed raised sugar levels. She faced complications including pre-eclampsia and a large baby, leaving her uncertain whether an earlier diagnosis would have changed the outcome, but she says a more thorough diagnostic pathway could have helped others.

Experts say there are steps that can help once gestational diabetes is diagnosed. Blood sugar can be controlled with medication in some cases, but diet and exercise are the most effective tools. Guidelines emphasize that four to five hours of moderate exercise per week can help, and a high fiber, low carbohydrate and low saturated fat diet can also make a significant difference. Health professionals say these lifestyle changes should be adopted even before a diagnosis to help prevent the condition from developing in the first place.

Foetal macrosomia has drawn attention on social media as mothers post videos of very large babies. The trend highlights that large babies are more likely to face birth injuries and later health problems. Doctors say undiagnosed gestational diabetes is a key risk factor for macrosomia, which is linked to shoulder injuries at birth and higher odds of obesity and type 2 diabetes later in life. The study notes that about one in ten UK children are now born weighing more than 8 pounds (3.5 kilograms), a marker of macrosomia.