Inter-relationship between evolutions of the temporal trend of urinary iodine excretion with iodized salt accessibility and thyroid function in an exclusive cohort of mothers residing in a mild iodine-deficient region

Abstract

Background and aims: Maternal iodine deficiency (UIC 4 and < 8 weeks) and non-pregnant women (n=40) with similar lifestyle and dietary habits were enrolled. UIC, TSH and table-salt iodine content were determined. Results: Median UIC (µg/L) according to trimesters was significantly lower than that of controls (61.6, 130.2 and 90.3 vs 133.8). Accordingly, prevalence of subjects with UIC<150 µg/L were 97.9, 67.4, 77.9 and 60. Median TSH (mIU/L) according to trimesters and control group were 1, 1.6, 1.4 and 1.6. Accordingly, prevalence of subjects with abnormal lower TSH limit was 17.2, 8.5, 3.2 and 2.4. Conclusion: This investigation demonstrates that UIC varies according to the foetal life cycle and that the highest frequencies of severe iodine (UIC <50 μg/L) were identified at the first- and third trimesters. This investigation paves the way for future studies aiming at exploring the therapeutic impact of iodine supplementation on body iodine stores during pregnancy.

Keywords

• thyroid stimulation hormone (tsh)
• urinary iodine excretion (uic)
• pregnancy
• iodine
• maternal iodine deficiency