New study underscores importance of early thyroid monitoring in pregnancy to potentially reduce autism risk

Emerging research highlights that thyroid problems in early pregnancy may influence neurodevelopmental outcomes, including autism, emphasising the need for vigilant testing and treatment.

A new analysis from the MARBLES cohort adds to evidence that thyroid problems in pregnancy may matter for a child’s later neurodevelopment, including the risk of autism. The study, published in a Wiley journal and supported by supplementary tables detailing hormone levels, pregnancy timing and child outcomes, examined maternal thyroid function measured by laboratory testing rather than self-report alone.

The findings fit into a wider body of research that has repeatedly raised concerns about thyroid dysfunction in early pregnancy. A Danish nationwide case-cohort study reported that maternal thyroid problems in early pregnancy were linked with a higher risk of neurodevelopmental disorders in children, including autism spectrum disorder and attention-deficit/hyperactivity disorder. A separate systematic review and meta-analysis also concluded that insufficient thyroid hormone during pregnancy, including subclinical hypothyroidism and isolated hypothyroxinaemia, has been associated with lower IQ scores and increased autism and ADHD risk.

Timing appears to matter. Earlier research on thyroid function in the second half of pregnancy found little convincing evidence of later developmental harm, suggesting the most sensitive window may be early gestation, when the fetal brain depends heavily on maternal hormone supply. That concern has also been echoed in more recent narrative reviews, which say prenatal thyroid dysfunction remains a plausible environmental factor in autism risk but needs further study because the evidence is still vulnerable to bias and misclassification.

Taken together, the research does not prove cause and effect, but it does strengthen the case for careful thyroid monitoring during pregnancy. The practical message for parents and caregivers is straightforward: thyroid disease in pregnancy is common enough, and potentially important enough, that timely testing and treatment may help reduce avoidable risk.