Ultrasonographic assessment of thyroid volume in Delhi children

Abstract

Background: Ultrasonographic measurement of thyroid volume is increasingly being used to assess prevalence of iodine deficiency in a community.

Objectives: To assess thyroid volume by ultrasonography in normal Delhi children, and compare them with the recently adopted WHO reference standards.

Methods: One hundred and three children aged of 6-10 years were enrolled from the paediatric outpatient clinic in a prospective study. Thyroid volume was estimated by ultrasound, and urinary iodine levels were measured for all subjects by spot urine samples.

Results: Goitre prevalence was 24.3% on clinical assessment. Urinary iodine levels fell in the range of mild to moderate deficiency in 61% of the children. None of the children met the WHO recommended ultrasonographic criteria for goitre (thyroid volume >97th percentile of the reference standards), when WHO age-specific norms were used for comparison. On applying body surface area (BSA)-specific norms, only two children were classified as having goitre.

Conclusions: The WHO standards for thyroid volume by ultrasonography tended to underestimate goitre prevalence.