Related Experiment Video
Updated: Jun 12, 2026
Generation of a Mouse Spontaneous Autoimmune Thyroiditis Model
Published on: March 17, 2023
Cord blood thyroid-stimulating hormone and free T4 levels in Turkish neonates: is iodine deficiency still a
Fatih Kişlal1, Semra Cetinkaya, Uğur Dilmen
1Clinic of Neonatology, Dr Zekai Tahir Burak Women's Health Education and Research Hospital, Ankara, Turkey.
Insights
Turkish neonates show thyroid-stimulating hormone (TSH) and free T(4) (FT(4)) levels indicating iodine deficiency remains a public health concern. These measurements aid in screening for congenital hypothyroidism and evaluating iodination programs.
Area of Science:
- Endocrinology
- Neonatal Health
- Public Health Nutrition
Background:
- Iodine deficiency disorders (IDDs) pose a significant global health challenge.
- Assessing thyroid function in neonates is crucial for early detection of developmental issues.
- Establishing normative thyroid hormone levels in specific populations is essential for accurate diagnosis.
Purpose of the Study:
- To establish normative cord blood thyroid-stimulating hormone (TSH) and free T(4) (FT(4)) levels in Turkish neonates.
- To evaluate the utility of these parameters in identifying iodine deficiency in the Turkish population.
- To provide data for screening programs for congenital hypothyroidism.
Main Methods:
- Cord blood samples were collected from 818 healthy Turkish neonates at birth.
- Thyroid-stimulating hormone (TSH) and free T(4) (FT(4)) levels were measured.
- Neonates were grouped based on cord serum TSH levels (<10 mIU/L vs. >10 mIU/L) for analysis.
Main Results:
- 72% of neonates had cord TSH < 10 mIU/L, while 28% had TSH > 10 mIU/L.
- Higher TSH levels (Group B) were associated with lower FT(4) levels (P < 0.05).
- Elevated TSH in males was observed at 41 weeks gestation and for birthweights < 2500g.
Conclusions:
- The study provides normative cord blood TSH and FT(4) data for Turkish neonates.
- Iodine deficiency is identified as an ongoing public health issue in Turkey.
- These thyroid hormone measurements are valuable for congenital hypothyroidism screening and assessing iodination program effectiveness.
Background:
The objectives of this study were to determine the cord blood thyroid-stimulating hormone (TSH) and free T(4) (FT(4) ) levels in Turkish neonates and to determine whether these variables reveal iodine deficiency.
Methods:
We collected 818 cords from healthy mothers at parturition and measured levels of FT(4) and TSH. We also measured cord blood FT(4) and TSH levels in different stages of gestation and gender. We grouped the neonates according to cord serum TSH levels, either being less (Group A) or greater (Group B) than 10 mIU/L. Group A included 589 neonates (300 girls [51%] and 289 boys [49%]) and Group B included 229 neonates (105 girls [45%] and 124 boys [55%]).
Results:
The percentage of subjects with cord blood TSH < 10 mIU/L and >10 mIU/L was 72% and 28%, respectively. Although cord TSH levels in Group B were greater than those in Group A (P < 0.001), cord blood FT(4) levels in Group B were lower than those in Group A (P < 0.05). There was no difference between both sex in terms of birthweight and maternal age. TSH and FT(4) levels did not vary according to neonate sex during gestation, except for from week 37 to 41. TSH levels of male neonates at the 41st week of gestation were higher than those of female neonates (P < 0.05). There were no effects of birthweight on TSH and FT(4) levels if the neonate was lighter than 2500 g at birth. TSH levels of male neonates were higher than those of female neonates when their birthweights were <2500 g (P < 0.05). There was no significant difference in TSH levels according to birthweights in male neonates.
Conclusion:
Our data provide the normative data for cord blood TSH and FT(4) levels in Turkish neonates and show that iodine deficiency is a still a public health problem in Turkey. These measurements can be useful for detection and verification of hypothyroidism in a screening program for congenital hypothyroidism as well as evaluation of the success of the iodination program.
Related Concept Videos
01:20Synthesis and Regulation of Thyroid Hormones
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The iodine is then...
01:25Hyperthyroidism I: Introduction
01:18Functions of Thyroid Hormones
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...
01:23Hypothyroidism II: Pathophysiology
01:27Hyperthyroidism II: Pathophysiology
01:27Goiter