A team of researchers states that intrauterine exposure to gestational diabetes mellitus is associated with an increased risk of autism spectrum disorders.
For the study, Anny H. Xiang of Kaiser Permanente Southern California (KPSC) in Pasadena and colleagues analyzed the prevalence of ASD among 322,323 children born between 1995 and 2009 at KPSC hospitals.
About 2 per cent of the children were born to mothers diagnosed with Type 2 diabetes before pregnancy, almost 8 per cent were exposed to gestational diabetes and 90 per cent were not exposed to any maternal diabetes.
The researchers found that when a pregnant woman develops diabetes during the first 26 weeks of gestation, her baby has an increased risk of developing autism spectrum disorder. In contrast, children born to women diagnosed with pregnancy-related diabetes after 26 weeks had no increased risk of having autism, nor did children whose mothers had diabetes before becoming pregnant.
No one knows what causes autism spectrum disorder, but researchers are learning more about it. Being born too early, too small, being born to older parents, having a sibling with autism
, being exposed to certain drugs or heavy metals during pregnancy - all are risk factors.
According to the authors, the association between intrauterine hyperglycemia and ASD risk could have multiple pathways. These include lower-than-normal concentrations of oxygen in the blood of the fetus and oxidative stress in the placental tissue and cord blood, during early critical brain development.