ESPE Abstracts

Objective: The primary aimof this study was to determine the normal values of thyroid gland size measured by ultrasonography (US) in healthy term newborn infants. The secondary objective was to compare the measurements made with handheld and standard US devices.

Materials and Methods: Healthy newborn infants aged 0-30 days were included in the study. Thyroid size was measured twice: first between days 1-2 and again between days 15-30. US measurements were performed by an endocrinologist using a point-of-care handheld US (Sonostar C5PL) and by an experienced radiologist using a portable US device (Samsung HM70 EVO). Thyroid volume was calculated as the sum of the volume of both lobes (cm³), using the formula: lobe width (cm) × depth (cm) × length (cm) × π/6. The tracheal index was calculated as the ratio of the sum of the right and left thyroid lobe widths to the width of the trachea. Data were presented as median values (25th-75th percentiles).

Results: A total of 144 healthy infants, 49.3% (n = 71) of whom were girls, were included in the study. Total thyroid volume between days 1-2 was 0.66 ± 0.25 mL; for girls, it was 0.64 ± 0.26 mL, and for boys, it was 0.68 ± 0.23 mL. Total thyroid volume between days 15-30 was 1.12 ± 0.33 mL; for girls, it was 1.12 ± 0.33 mL, and for boys, it was 1.13 ± 0.33 mL. Thyroid size increased significantly between days 15-30 in both sexes. There was a positive, moderate correlation between birth weight, length, and head circumference SDS and initial thyroid volume. The tracheal index between days 1-2 was 1.83 ± 0.29, while it was 1.99 ± 0.25 between days 15-30, with no significant difference between genders. Thyroid volume and tracheal index were moderately correlated in both the first and second measurements (rho: 0.538, P <0.01). There was a good correlation in the first measurement and a moderate positive correlation in the second measurement with handheld and portable USG devices (rho: 0.660, P <0.001; rho: 0.416, P <0.001, respectively).

Conclusion: This study presents the normal values of thyroid volumes in healthy Turkish infants born in Aydın. Thyroid volume is correlated with birth weight, height, and head circumference, showing dynamic changes in the first two weeks. In cases where it is not possible to evaluate the three dimensions, the tracheal index may provide an indication of thyroid gland size. Bedside measurements with a handheld device can be used effectively for evaluating the neonatal thyroid gland.