Should the levothyroxine starting dose be tailored to disease severity in neonates with congenital hypothyroidism?

Stephen H. LaFranchi

Research output: Contribution to journalShort surveypeer-review

5 Scopus citations


Early levothyroxine treatment is crucial to minimize neurocognitive impairment associated with congenital hypothyroidism. In this Practice Point commentary, I discuss the findings, implications, and limitations of the study of Mathai et al. in which neonates with congenital hypothyroidism were treated with variable initial doses of levothyroxine. A high initial levothyroxine dose was used for newborn babies with athyreosis, an intermediate dose for those with ectopic glands, and a low dose for those with dyshormonogenesis. Serum free T4 levels normalized within 2 weeks, but serum TSH levels within up to 4 weeks. A dose adjustment (mostly a dose reduction) was required in about half of the neonates in the first 2 weeks of life. As Mathai et al. carried out no neuropsychological tests, we do not know if their approach has a more beneficial effect on neurocognitive outcomes than other treatment strategies. Nevertheless, as tailoring the levothyroxine dose to severity rapidly normalized serum free T4 levels, one would predict a beneficial effect of this approach on neurocognitive outcome.

Original languageEnglish (US)
Pages (from-to)658-659
Number of pages2
JournalNature Clinical Practice Endocrinology and Metabolism
Issue number12
StatePublished - Dec 2008
Externally publishedYes


  • Congenital hypothyroidism
  • Free T
  • Newborn screening
  • TSH
  • Thyroid scintigraphy scan

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology


Dive into the research topics of 'Should the levothyroxine starting dose be tailored to disease severity in neonates with congenital hypothyroidism?'. Together they form a unique fingerprint.

Cite this