Maternal Thyroid Function in Early Pregnancy and Neuropsychological Performance of the Child at 5 Years of Age

J Clin Endocrinol Metab. 2018 Feb 1;103(2):660-670. doi: 10.1210/jc.2017-02171.


Context: Abnormal maternal thyroid function in pregnancy may impair fetal brain development, but more evidence is needed to refine and corroborate the hypothesis.

Objective: To estimate the association between maternal thyroid function in early pregnancy and neuropsychological performance of the child at 5 years of age.

Design: Follow-up study.

Participants: A cohort of 1153 women and their children sampled from the Danish National Birth Cohort. Maternal thyroid-stimulating hormone (TSH) and free thyroxine (fT4) were measured in stored biobank sera from early pregnancy.

Main outcomes measures: Child neuropsychological test results (Wechsler Intelligence Scale/Test of Everyday Attention), test of motor function (Movement Assessment Battery), and results of parent and teacher reports (Behavior Rating Inventory of Executive Function/Strengths and Difficulties Questionnaire).

Results: Altogether 145 children (12.6%) were born to mothers with abnormal thyroid function in the early pregnancy. High maternal TSH and low fT4 were associated with lower child verbal intelligence quotient (adjusted mean difference TSH ≥ 10 mIU/L vs 0.1 to 2.49 mIU/L, -8.9 [95% confidence interval (CI), -15 to -2.4]; fT4 < 10 pmol/l vs 12.0 to 18.99 pmol/l, -13 [95% CI, -19 to -7.3]). Abnormal maternal thyroid function was also associated with adverse motor function and teacher-reported problems of executive function and behavior, and these associations were dominated by exposure to maternal hypothyroxinemia.

Conclusions: Maternal thyroid hormone abnormalities were associated with adverse neuropsychological function of the child at 5 years of age. For intelligence, marked hypothyroidism was important, whereas for motor function and executive and behavior problems, maternal hypothyroxinemia was predominant.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Child Development / physiology*
  • Child, Preschool
  • Cohort Studies
  • Denmark / epidemiology
  • Female
  • Follow-Up Studies
  • Humans
  • Intelligence / physiology*
  • Male
  • Mothers*
  • Neuropsychological Tests
  • Pregnancy
  • Prenatal Exposure Delayed Effects / blood
  • Prenatal Exposure Delayed Effects / epidemiology
  • Prenatal Exposure Delayed Effects / psychology*
  • Thyroid Function Tests / statistics & numerical data
  • Thyroid Gland / physiology*
  • Young Adult