Repeated potassium iodide exposure during pregnancy impairs progeny's brain development

Area of Science:

• Endocrinology
• Neuroscience
• Developmental Biology

Background:

• Radioiodine release necessitates potassium iodide (KI) for thyroid protection.
• Iodine excess transiently inhibits thyroid function, posing risks to fetal development dependent on maternal thyroid hormones (TH).
• Subtle maternal thyroid function variations can have lasting effects on offspring brain processing.

Purpose of the Study:

• To investigate the effects of repeated KI intake during pregnancy on progeny's thyroid function and brain development.
• To assess long-term neurodevelopmental consequences in offspring exposed to maternal KI prophylaxis.

Main Methods:

• Pregnant Wistar rats received KI for eight days.
• Male progeny were assessed 30 days post-weaning for behavioral tests, hormone levels, antibody levels, organ morphology, gene expression, and DNA methylation.
• Key genes (DCX, RC3, MBP, MOBP, Kcna1) and hormone levels (TSH, fT4) were analyzed.

Main Results:

• KI-exposed male progeny exhibited decreased thyroid-stimulating hormone (TSH) and free thyroxine (fT4) levels.
• Altered motor coordination was observed in KI-exposed male progeny.
• Significant changes in cerebellar and cortical gene expression related to neurodevelopment were noted.

Conclusions:

• Repeated KI prophylaxis during pregnancy is not suitable due to potential long-term neurotoxicity in male offspring.
• Maternal iodine excess can lead to irreversible neurodevelopmental deficits.
• Further research is needed to understand the full impact of iodine prophylaxis on fetal neurodevelopment.