Iodine Deficiency in Northern Paris Area: Impact on Fetal Thyroid Mensuration

INTRODUCTION Iodine is essential for normal fetal and neonatal development. We studied the prevalence and impact on fetal thyroid development of iodine deficiency in pregnant women in the northern part of the Paris conurbation. MATERIALS AND METHODS 110 patients underwent several determinations of urinary iodine excretion (UIE) and of serum FT4, FT3, and TSH. Fetal thyroid gland size was assessed using ultrasonography. RESULTS We found evidence of widespread iodine deficiency (mean UIE, 49.8 µg/L [standard deviation, 2.11]). Iodine deficiency did not correlate significantly with maternal thyroid parameters but showed a significant negative correlation with fetal thyroid gland size (rho = 0.25, P = 0.02). CONCLUSION Iodine deficiency during pregnancy is still a problem in our geographical area and affects the fetal thyroid gland. Clinical Trials.gov NCT00162539.