Chronic hypothyroidism in mothers tied to increased risk of autism.

Thyroid hormones are essential for fetal neurogenesis and maturation, with the fetus relying largely on maternal derived hormone via placental transfer, particularly in the first trimester," they explained. "Consequently, disruptions in maternal thyroid hormone levels during pregnancy have been associated with adverse developmental outcomes in offspring, including lower IQ scores and delays in expressive language and nonverbal cognition.