Evaluation of iodine status and its relationship with capilllary TSH in pregnant women and newborn babies in Aydin province

Background: In this cross-sectional-analytical study, we aimed to investigate the iodine status of pregnant women and their babies by measuring urinary iodine levels in Aydın, and to evaluate the relationship between the iodine status of the subjects and cord blood thyrotropin stimulating hormone (TSH) levels. Material-Method: Pregnant women and newborn babies living in Aydın between March 1, 2021 and January 20, 2022 were included in the study. A questionnaire including demographic, and clinical features such as socioeconomic and obstetric characteristics of pregnant women, thyroid diseases, iodized salt use, iodine supplementation during pregnancy and birth characteristics of newborn babies was applied. By measuring the median urinary iodine concentration (mUIC) and cord blood TSH as indicators of iodine status, the mUIC <150 μg/L in pregnant women, and mUIC <100 μg/L in newborns was defined as iodine deficiency. The frequency of infants with a cord blood TSH level of >10 mIU/L and its relation with iodine status were investigated. Results: Three hundred eighty-eight pregnant women and newborn babies were included in the study, 153 pregnant women and newborns were excluded due to iodine excess (>500 μg/L), and the analysis was performed on 235 participants. mUIC in pregnant women and newborns was 144.8 μg/L and 143.0 μg/L, and the frequency of iodine deficiency was 51.9% and 35.3 respectively. The frequency of severe, moderate and mild iodine deficiency in pregnants was 16.4% (n=20), 33.6% (n=41), and 50.0% (n=61), respectively. The frequency of severe, moderate and mild iodine deficiency in newborns was 12% (n=10), 18.1% (n=15), and 69.9% (n=58), respectively. A significant positive correlation was found between newborn and mother mUIC (rho=0.383 p<0.001). The frequency of infants with cord blood TSH >10 mIU/L was 2.7%. There was no correlation between mUIC and cord blood TSH levels in pregnant women and newborns (p>0.05). Maternal age and iodized salt usage was related to iodine status of pregnant women. Conclusion: The results of this study show that there is mild iodine deficiency in pregnant women, and iodine is sufficient in newborns in Aydın, according to the iodine status determined by mUIC. Therefore, we need for strategies to improve the iodine status of pregnant women in Aydın.