Association between maternal hypothyroidism and autism spectrum disorders in children

Area of Science:

• Endocrinology
• Neurodevelopmental Disorders
• Perinatal Health

Background:

• Autism spectrum disorders (ASD) are complex neurodevelopmental conditions with multifactorial etiologies.
• Maternal health conditions during pregnancy are increasingly recognized as potential environmental factors influencing fetal development.
• The role of hypothyroidism, a common endocrine disorder, in the etiology of ASD requires further investigation.

Purpose of the Study:

• To investigate the association between maternal hypothyroidism and the risk of autism spectrum disorders (ASD) in offspring.
• To examine how this association is modified by factors such as race-ethnicity, sex, and the timing of hypothyroid diagnosis (pre-pregnancy vs. during pregnancy).

Main Methods:

• A retrospective cohort study utilizing health plan records of 397,201 children born between 1991 and 2011.
• Analysis included children with maternal hypothyroidism (diagnosed before or during pregnancy) and a control group.
• Statistical methods, including adjusted hazard ratios (adj.HR) and confidence intervals (CI), were used to assess risk.

Main Results:

• Children born to mothers with hypothyroidism exhibited higher ASD rates compared to children of mothers without the diagnosis (adj.HR, 1.31).
• The association between maternal hypothyroidism and ASD was observed in both boys and girls, with a stronger effect noted in girls.
• Prenatal hypothyroidism showed a differential association with ASD risk across racial-ethnic groups, notably increasing risk in Hispanic and other/mixed race children compared to white children.

Conclusions:

• Maternal hypothyroidism is significantly associated with an increased risk of ASD in children.
• The observed association is influenced by the child's race-ethnicity.
• Effective management of maternal hypothyroidism during pregnancy may be a potential strategy to mitigate ASD risk.