Maternal Thyroid Hormone Replacement Therapy Exposure and Language and Communication Skills of Offspring at 8 Years of Age

Key Points Question Is prenatal exposure to thyroid hormone replacement therapy associated with children’s language, speech, and communication skills at 8 years of age? Findings In this nationwide population-based cohort linkage study of 53 862 mother-child pairs in Norway, prenatal thyroid hormone replacement therapy exposure was not associated with diagnoses and symptoms of child language and speech impairment, compared with the group not exposed to thyroid hormone replacement therapy or the group that received thyroid hormone replacement therapy after delivery. Meaning These findings indicate that the children of mothers treated with thyroid hormone replacement therapy for hypothyroidism were not associated with symptoms of or increased risk of language impairment.