OBJECTIVE: @entity1375 in pregnant @entity1 is associated with a lower intelligence quotient in their @entity1 . More recently, subtle decreases in maternal thyroid function have also been associated with @entity245 in offspring. We tested the effect of hypothyroxinaemia during early pregnancy on school performance. DESIGN: This was a longitudinal study that included the data of 1,196 mother- @entity1 pairs from the Amsterdam Born @entity1 and their Development study. METHODS: Maternal serum free T4 and TSH were obtained at a median gestational age of 12.9 (interquartile range: 11.9-14.3) weeks. School performance was assessed at age 5 years and based on scores obtained in arithmetics and language tests from the national monitoring and evaluation system. Poor school performance was defined as a test result <25th percentile and subnormal school performance as a result <50th percentile of the norm population. To estimate the impact of possible non-response bias, we conducted inverse-probability weighted analyses. RESULTS: @entity7310 (i.e., a maternal free T4 in the lowest 10% of distribution) was associated with a 1.61 (95% confidence interval (CI): 1.05-2.47) -fold increased odds of subnormal arithmetic performance after adjustment for confounders (p= 0.03). However, the odds ratio dropped to 1.48 (95% CI: 0.94-2.32) after inverse-probability weighting (p= 0.09). No such relations were found with TSH. CONCLUSIONS: Maternal hypothyroxinemia at the end of the first trimester was associated with reduced performance in an arithmetics test, but not in a language test, in 5-year-old offspring. However, our results should be interpreted carefully, because of possible non-response bias.

XXXX in early pregnancy and school performance in 5-year-old offspring.

@entity1 :: ('9606', 'Species') :: ['women', 'children', 'Children', 'child'] @entity1375 :: ('MESH:D007037', 'Disease') :: ['Overt hypothyroidism'] @entity7310 :: ('MESH:C536469', 'Disease') :: ['Maternal hypothyroxinaemia'] @entity245 :: ('MESH:D002658', 'Disease') :: ['neurodevelopmental impairment']
@entity7310 :: (MESH:C536469,Disease) :: ['Maternal hypothyroxinaemia']
