Normative Values for Thyroid Volume and Tracheal Index in Healthy Turkish Newborns in an Iodine Sufficient Region.

Abstract

The study aims to determine the normal values of thyroid volume and tracheal index in healthy term newborns born in an iodine-sufficient population. Additionally, we investigated the usability of a handheld device for assessing the tracheal index. Thyroid imaging was performed at 0-2 days and 15-30 days using handheld and portable ultrasound devices. Thyroid volume and tracheal index were calculated using standard formulas. A total of 144 healthy term newborns with a mean birth weight 3230 g were enrolled. The normal thyroid volume for the entire population was 0.66 ± 0.25 ml at 0-2 days, which significantly increased to 1.12 ± 0.33 ml at 15-30 days (p<0.01). There were no significant differences in thyroid volume between genders in either age group (p=0.246 and p=0.879). Thyroid volume correlated with birth weight, length, and head circumference, with the strongest correlation being with birth weight (r=0.404, p<0.001; r=0.252, p=0.002; r=0.223, p=0.007, respectively). The tracheal index at 0-2 days was 1.84±0.30 in girls, 1.82±0.27 in boys, and 1.83±0.29 overall. At 15-30 days, it was 1.99±0.23 in girls, 2.00±0.28 in boys, and 1.99±0.25 overall. Similar to thyroid volume, the tracheal index increased with age (p<0.01), with no significant gender differences in either age group (p=0.593 and p=0.886). Thyroid volume and tracheal index were moderately correlated in both measurements (rho=0.538, p<0.01). Measurements of the trachea, and thyroid lobe widths using portable and handheld ultrasound devices were correlated (r=0.449, p<0.01; r=0.638, p<0.01; r=0.497, p<0.01). There was also a correlation between tracheal index measurements using both devices in both the first and second measurements. This study provides normative data on thyroid volumes and tracheal index in newborns from an iodine-sufficient population. The tracheal index can estimate thyroid size when volume calculation is not feasible and handheld ultrasound devices are effective for this assessment.