Antenatal thyroid disease and pharmacotherapy in pregnancy

Thyroid disease is one of the most common endocrine pathologies treated in pregnancy. This chapter discusses the diagnosis of thyroid disease in pregnancy and its appropriate medical management. There are various normal changes of the thyroid gland in pregnancy, which can complicate the diagnosis of thyroid disease. We present an explanation of these normal thyroid function changes in pregnancy as well as the laboratory values which are affected. We then discuss the etiology, diagnosis, and management of hyperthyroidism and hypothyroidism. Appropriate management of hyperthyroidism is essential to the safety of the fetus due to the necessity of trimester-specific antithyroid drug strategy. Hypothyroidism is usually well tolerated in pregnancy and can be managed with levothyroxine. By the end of this chapter, readers will understand the definition of each condition, the clinical and laboratory criteria needed for their diagnosis, and the proper treatment.