Current status of iodisation in pregnant women in Asturias, Spain

Although former studies indicated that Asturias (Spain) is an iodine-sufficient region, preliminary data suggest this trend may be changing.

To determine the prevalence of iodine deficiency in pregnant women in Asturias.

We designed an observational, prospective, multicenter study. The urinary iodine concentration (UIC) of 371 pregnant women was analyzed between November 2021 and March 2023. Participants were recruited from the three central areas of the Principality of Asturias (Areas III, IV, and V). The project received approval from the Research Ethics Committee of the Principality of Asturias (RECPA).

A total of 52% of pregnant women had urinary iodine levels indicative of iodine deficiency (< 150 μg/L). The average UIC in our cohort was 146 μg/L. We compared thyroid-stimulating hormone (TSH) levels between pregnant women with iodine deficiency and those with sufficient iodine, but found no statistically significant differences in TSH levels between the two groups. We also couldn't establish statistically significant links between iodine deficiency status and body mass index (BMI), number of previous births, nationality, or age. Furthermore, iodine deficiency did not show a significant link to obstetric complications such such as hypertension during pregnancy or premature birth.

These findings support the hypothesis of an increase in iodine deficiency during the first trimester of pregnancy in our population. This highlights the urgent need to review our supplementation strategies and nutritional education programs.