Thyroid autoimmunity in euthyroid pregnant women is associated with slower productive language acquisition: the Odense child cohort study.

In women without known thyroid disease, TPOAb positivity in early pregnancy was negatively associated with productive vocabulary acquisition in girls and boys. This association was not mediated by a decreased thyroid function, as low-normal maternal FT4, unexpectedly, indicated better vocabulary acquisition. Our results support that maternal thyroid autoimmunity per se may affect fetal neurodevelopment.