22. Hypothyroidism and Hyperthyroidism

  1. John T. Queenan MD2,
  2. Catherine Y. Spong MD3 and
  3. Charles J. Lockwood MD4
  1. Brian Casey MD

Published Online: 4 JAN 2012

DOI: 10.1002/9781119963783.ch22

Queenan's Management of High-Risk Pregnancy: An Evidence-Based Approach, Sixth Edition

Queenan's Management of High-Risk Pregnancy: An Evidence-Based Approach, Sixth Edition

How to Cite

Casey, B. (2012) Hypothyroidism and Hyperthyroidism, in Queenan's Management of High-Risk Pregnancy: An Evidence-Based Approach, Sixth Edition (eds J. T. Queenan, C. Y. Spong and C. J. Lockwood), Wiley-Blackwell, Oxford, UK. doi: 10.1002/9781119963783.ch22

Editor Information

  1. 2

    Department of Obstetrics and Gynecology, Georgetown University School of Medicine, Washington, DC, USA

  2. 3

    Bethesda, MD, USA

  3. 4

    Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA

Author Information

  1. Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX, USA

Publication History

  1. Published Online: 4 JAN 2012
  2. Published Print: 24 FEB 2012

ISBN Information

Print ISBN: 9780470655764

Online ISBN: 9781119963783



  • hypothyroidism and hyperthyroidism;
  • hypothyroidism, complicating 1–3 in 1000 pregnancies;
  • subclinical hypothyroidism, affecting 2–3%;
  • Hashimoto thyroiditis, primary hypothyroidism in pregnancy;
  • clinical hypothyroidism diagnosis in pregnancy, difficult;
  • hypothyroidism, elevated serum TSH, low serum fT4;
  • overt hypothyroidism, clinical, biochemical euthyroidism;
  • hyperthyroidism, complicating 1–2 in 1000;
  • Graves disease, organ-specific autoimmune process;
  • thyroid storm and heart failure, exacerbations of thyrotoxicosis


Hypothyroidism complicates 1–3 in 1000 pregnancies. Women with overt hypothyroidism are at an increased risk for complications such as early pregnancy failure, preeclampsia, placental abruption, low birthweight, and stillbirth. Treatment of women with hypothyroidism has been associated with improved pregnancy outcomes. The most common cause of primary hypothyroidism in pregnancy is chronic autoimmune thyroiditis (Hashimoto thyroiditis). This is a painless inflammation with progressive enlargement of the thyroid gland which is characterized by diffuse lymphocytic infiltration, fibrosis, parenchymal atrophy, and eosinophilic change. Other important causes of primary hypothyroidism include endemic iodine deficiency and a history of either ablative radio-iodine therapy or thyroidectomy.

Hyperthyroidism complicates approximately 1–2 in 1000 pregnancies. The overwhelming cause of hyperthyroidism during pregnancy is Graves disease or autoimmune thyrotoxicosis. Pregnant women with hyperthyroidism are at increased risk for congestive heart failure, thyroid storm, preterm labor, preeclampsia, fetal growth restriction, and perinatal mortality. Treatment of hyperthyroid women to achieve adequate metabolic control will result in improved pregnancy outcomes.