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Longitudinal study of thyroid function in children with mild hyperthyrotropinemia at neonatal screening for

Daniela Leonardi1, Nunziella Polizzotti, Anna Carta

  • 1Endocrinologia-Università di Catania, Ospedale Garibaldi-Nesima, Via Palermo 636, Catania, Italy.

The Journal of Clinical Endocrinology and Metabolism
|May 1, 2008
PubMed

Insights

Neonatal screening "false positives" for hyperthyrotropinemia face a high risk of persistent subclinical hypothyroidism into childhood. While prevalence decreases with age, it remains significant, indicating potential minor congenital thyroid abnormalities.

Area of Science:

  • Pediatric Endocrinology
  • Neonatal Screening
  • Thyroid Function

Background:

  • Neonatal screening for congenital hypothyroidism identifies infants with elevated thyroid-stimulating hormone (TSH).
  • Very short-lasting neonatal hyperthyrotropinemia, termed "false positives," can occur, with some infants previously showing high TSH prevalence of subclinical hypothyroidism in early childhood.

Purpose of the Study:

  • To investigate the long-term thyroid function and morphology outcomes in children with "false positive" neonatal screening results.
  • To assess the persistence of subclinical hypothyroidism from early to late childhood in this cohort.

Main Methods:

  • An observational, prospective study evaluated 44 children with "false positive" neonatal screening results.
  • Thyroid function (TSH, free T3) and morphology were assessed up to advanced childhood (average age 8.0 years).
  • Data were compared to control children with normal neonatal TSH levels.

Main Results:

  • Subclinical hypothyroidism persisted in 43.2% at age 5.3 years and 31.8% at age 8.0 years.
  • Children maintaining euthyroidism had significantly higher TSH and free T3 levels than controls.
  • Thyroid morphology alterations were common in children with persistent subclinical hypothyroidism.

Conclusions:

  • Newborns with "false positive" neonatal screening results have a high risk for persistent subclinical hypothyroidism.
  • Hypothyroidism prevalence decreases with age but remains elevated (>30%) in late childhood.
  • Elevated TSH in euthyroid "false positive" children suggests potential minor congenital thyroid function abnormalities.
Abstract

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