Maternal Thyroid Function in Early Pregnancy and Offspring School Performance and Neurodevelopmental Disorders

Area of Science:

• Neuroscience
• Endocrinology
• Developmental Biology

Background:

• Thyroid hormones are essential for fetal neural development.
• The fetus is entirely dependent on maternal thyroid hormones during the first trimester of pregnancy.

Purpose of the Study:

• To examine the relationship between first-trimester maternal thyroid hormone levels and children's academic achievement.
• To investigate the association between maternal thyroid hormone levels and the risk of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in offspring.

Main Methods:

• Utilized data from the Copenhagen Primary Care Laboratory Pregnancy Database, linking maternal thyroid-stimulating hormone (TSH) and free thyroxine measurements with child outcomes.
• Employed linear mixed models and Cox regression to assess associations, with analyses stratified by pre-existing maternal thyroid conditions.
• Included 17,909 mother-child dyads for ADHD and ASD risk analysis, and 6,126 for school performance analysis.

Main Results:

• No association was found between first-trimester maternal thyroid hormone levels and children's standardized school test scores.
• Maternal thyroid hormone levels in early pregnancy showed no association with the risk of ADHD or ASD in children.
• Stratifying analyses by pre-existing maternal thyroid disorders did not alter the observed results.

Conclusions:

• This study found no evidence linking first-trimester maternal thyroid hormone levels to children's school performance.
• No association was identified between maternal thyroid hormone levels during early pregnancy and the risk of ADHD or ASD.
• These findings suggest maternal thyroid function in early pregnancy may not be a significant factor for these specific neurodevelopmental outcomes.