Recommended normative values for thyroid volume in children aged 6-15 years. World Health Organization & International Council for Control of Iodine Deficiency Disorders

Abstract

Inspection and palpation are the traditional methods used to determine thyroid volume in areas of moderate-to-severe iodine deficiency. However, in areas of mild endemicity, and generally whenever goitres are small, ultrasonography is a safe, noninvasive technique that provides a more precise and objective method for determining thyroid volume. Ultrasonography should be undertaken by well-trained operators, whose correct interpretation relies on the availability of standardized reference criteria from populations whose iodine status is known to be adequate. A recent survey conducted among schoolchildren aged 6-15 years in 12 European countries provides ultrasound data for determining thyroid volume from 7599 subjects, and urinary iodine levels from 5709 subjects. A subgroup of 3474 children born and living in areas where iodine intake is normal-as evidenced by median urinary iodine above 100 micrograms/l-furnishes data from which to derive thyroid volume reference values. This article presents the upper normal limit for thyroid volume, according to age, for the iodine-replete boys and girls in this subgroup, assessed using ultrasonography. In countries with a high prevalence of child growth retardation, thyroid volume is provisionally considered to be more directly a function of total body surface area. Recommended upper normal limits of thyroid volume, calculated according to body surface area, are also reported. These cut-off values are recommended for interpreting survey and surveillance ultrasonography data among school-age children.