Research published in the Journal of Pediatrics (September 2011; 159(3):447–453) examined the relationship between maternal thyroid function during pregnancy and early childhood development.
In this study, maternal free thyroxine (free T4) levels were measured during the first trimester of pregnancy. A total of 86 children were then assessed at 12, 18, and 24 months of age using the Bayley Scales of Infant Development.
The researchers found a significant association between maternal free T4 levels and children’s psychomotor development at 18 and 24 months. Children born to mothers whose free thyroxine levels were in the lowest 25th percentile showed more developmental delay compared with children of mothers with higher free T4 levels.
The authors interpreted these findings as evidence that adequate maternal thyroid hormone availability during early pregnancy is important for normal neurodevelopment. They noted that iodine status, which influences thyroid hormone production, may be particularly relevant before conception and during pregnancy and lactation.
