Postpartum thyroid dysfunction

The most common cause of postpartum thyroid dysfunction is postpartum thyroiditis. Postpartum thyroiditis typically causes transient hyperthyroidism (due to release of preformed thyroid hormone from damaged thyroid follicles), followed by hypothyroidism. Both phases are usually mild and transient, and most women revert to euthyroidism within a year postpartum. Elevated thyroid peroxidase antibody is associated with more severe disease, which may require treatment—beta blockers for symptom control during the hyperthyroid phase, and short-term thyroxine replacement during the hypothyroid phase. Antithyroid drugs are not effective during the hyperthyroid phase.

Postpartum thyroiditis must be differentiated from new-onset or relapsing Graves disease, which usually requires antithyroid treatment. Positive TSH-receptor antibody suggests Graves disease. The risk of relapse in women with remitted Graves disease is higher in the postpartum period.

Women who have had postpartum thyroid dysfunction are at increased risk of developing hypothyroidism in the 10 years postpartum. Counsel women about the symptoms of hypothyroidism and advise them to seek medical advice if symptoms occur.