Prenatal and neonatal thyroid stimulating hormone levels and autism spectrum disorders

Area of Science:

• Neurodevelopmental disorders
• Endocrinology
• Maternal-fetal medicine

Background:

• Thyroid hormones are essential for fetal brain development.
• Disruptions in thyroid function during pregnancy are implicated in neurodevelopmental outcomes.
• Autism spectrum disorder (ASD) is a complex neurodevelopmental condition with potential environmental influences.

Purpose of the Study:

• To investigate the association between thyroid stimulating hormone (TSH) levels during pregnancy and the risk of autism spectrum disorder (ASD).
• To compare TSH levels in maternal serum and infant blood between children with ASD, developmental delay, and general population controls.

Main Methods:

• Retrospective cohort study using maternal serum and infant blood samples from prenatal and newborn screening archives.
• Participants included children diagnosed with ASD (n=78), developmental delay (n=45), and general population controls (n=149).
• Adjusted logistic regression models were used to analyze the association between log-transformed TSH levels and ASD diagnosis.

Main Results:

• An inverse association was found between autism spectrum disorder and log-transformed thyroid stimulating hormone (TSH) levels in mid-pregnancy maternal serum (ASD vs. GP: OR 0.33 [0.12-0.91]).
• Early onset ASD also showed an inverse association with maternal TSH levels (Early Onset ASD vs. GP: 0.31 [0.10-0.98]).
• Similar trends were observed for TSH levels in newborn blood, but these did not reach statistical significance.

Conclusions:

• Lower maternal serum TSH levels in mid-pregnancy may be associated with an increased risk of autism spectrum disorder.
• The findings suggest a potential role for maternal thyroid function in the etiology of ASD.
• Further research is needed to confirm these findings and explore the underlying biological mechanisms.