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Thyroid gland

Early adjustment of levothyroxine treatment in pregnancy

The THERAPY trial investigators conclude that, when pregnancy is confirmed in adequately treated women with hypothyroidism, doubling the dose of prepregnancy levothyroxine on 2 days each week safely prevents maternal hypothyroidism in the first trimester of pregnancy in most cases. Is this really the best strategy to adopt?

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References

  1. Abalovich, M. et al. Overt and subclinical hypothyroidism complicating pregnancy. Thyroid 12, 63–68 (2002).

    Article  CAS  PubMed  Google Scholar 

  2. Haddow, J. E. et al. Maternal thyroid deficiency during pregnancy and subsequent neuropsychological development of the child. N. Engl. J. Med. 341, 549–555 (1999).

    Article  CAS  PubMed  Google Scholar 

  3. Alexander, E. K. et al. Timing and magnitude of increases in levothyroxine requirements during pregnancy in women with hypothyroidism. N. Engl. J. Med. 351, 241–249 (2004).

    Article  CAS  PubMed  Google Scholar 

  4. Yassa, L., Marqusee, E., Fawcett, R. & Alexander, E. K. Thyroid hormone early adjustment in pregnancy (the THERAPY) trial. J. Clin. Endocrinol. Metab. 95, 3234–3241 (2010).

    Article  CAS  PubMed  Google Scholar 

  5. Casey, B. M. et al. Subclinical hypothyroidism and pregnancy outcomes. Obstet. Gynecol. 105, 239–245 (2005).

    Article  PubMed  Google Scholar 

  6. Abalovich, M. et al. Management of thyroid dysfunction during pregnancy and postpartum: An endocrine society clinical practice guideline. J. Clin. Endocrinol. Metab. 92, S1–S47 (2007).

    Article  CAS  PubMed  Google Scholar 

  7. Casey, B. M. et al. Subclinical hyperthyroidism and pregnancy outcomes. Obstet. Gynecol. 107, 337–341 (2006).

    Article  PubMed  Google Scholar 

  8. Kuppens, S. M. et al. Maternal thyroid function during gestation is related to breech presentation at term. Clin. Endocrinol. (Oxf.) 72, 820–824 (2010).

    Article  CAS  Google Scholar 

  9. Wijnen, H. A. et al. Maternal thyroid hormone concentration during late gestation is associated with foetal position at birth. Clin. Endocrinol. (Oxf.) 71, 746–751 (2009).

    Article  CAS  Google Scholar 

  10. Verga, U. et al. Adjustment of levothyroxine substitutive therapy in pregnant women with subclinical, overt or post-ablative hypothyroidism. Clin. Endocrinol. (Oxf.) 70, 798–802 (2009).

    Article  CAS  Google Scholar 

Download references

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Chan, S. Early adjustment of levothyroxine treatment in pregnancy. Nat Rev Endocrinol 6, 537–538 (2010). https://doi.org/10.1038/nrendo.2010.149

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