Graves Disease in Pregnancy

Post date: Apr 28, 2010 12:44:41 AM

The endocrinologist has a very important role in the counseling and management of women with active Graves disease during pregnancy or in women who have the disease and want to conceive. Gestational thyrotoxicosis is the most common form of hyperthyroidism in pregnancy followed by Graves hyperthyroidism. These two conditions may be difficult to differentiate in the first trimester. Antithyroid medications (propylthiouricil and methimazole) remain the main way to treat hyperthyroidism in pregnancy. The goal of treatment with these medications is to achieve Free T4 Index (FTI) levels in the upper one third of the normal range with medication adjustments every 2-4 weeks. The FTI remains constant during pregnancy and avoids the mis-diagnosis of 'hypothyroxinemia'. Previous recommendations had suggested the use of the direct Free T4 (FT4) assay, but this method is flawed if non pregnant reference ranges are used since the levels of FT4 decrease below the normal range in the second and third trimesters.