Associations between maternal thyroid function in pregnancy and child neurodevelopmental outcomes at 20 months in the...

Area of Science:

• Endocrinology
• Neurodevelopmental Biology
• Maternal-Fetal Medicine

Background:

• Maternal thyroid hormones are essential for fetal brain development.
• The precise impact of maternal thyroid function on specific cognitive outcomes remains unclear.
• Optimal maternal thyroid hormone levels are critical during pregnancy.

Purpose of the Study:

• To investigate the association between maternal thyroid hormone levels (free triiodothyronine [fT3], free thyroxine [fT4], and thyroid-stimulating hormone [fTSH]) and neurodevelopmental outcomes in offspring.
• To explore these associations within the Seychelles Child Development Study (SCDS) Nutrition 2 cohort.

Main Methods:

• Maternal serum thyroid hormone levels were measured at 28 weeks' gestation.
• Child cognitive outcomes were assessed at 20 months of age.
• Linear regression analysis was employed to examine associations, with hormones analyzed continuously and by quintiles.

Main Results:

• Ninety-five percent of mothers exhibited optimal thyroid function based on fTSH levels.
• Overall maternal thyroid function was not significantly associated with child neurodevelopmental outcomes in this population.
• A positive association was observed between higher quintiles of maternal fT3 and the Mental Developmental Index, suggesting potential impacts of minor fT3 imbalances.

Conclusions:

• Maternal thyroid function and iodine intake appear adequate in this high fish-eating population, with mothers regulating thyroid function to support fetal neurodevelopment.
• Minor fluctuations in maternal free triiodothyronine (fT3) may warrant further investigation for their impact on offspring neurodevelopment.
• Additional research is needed, especially in diverse populations with varying dietary iodine intakes, to fully understand the maternal thyroid function-neurodevelopment relationship.