Endocrine Abstracts

Hyperthyroidism in pregnancy should be adequately managed to prevent maternal and fetal complications. The diagnosing of hyperthyroidism in pregnant women is challenged by the physiological alterations in thyroid function tests. Furthermore, the distinction between gestational hyperthyroidism and the hyperthyroidism of Graves’ disease presents a clinical challenge. Graves’ disease is an autoimmune disorder associated with the presence of thyroid stimulating hormone-receptor antibodies, and the immunological alterations in and after a pregnancy affect the incidence and the manifestation of the disease. An important clinical focus is on the treatment of hyperthyroidism caused by Graves’ disease in women of fertile age who are or may in the future become pregnant. Antithyroid drugs (ATDs) constitute a recognized treatment of hyperthyroidism in non-pregnant and pregnant individuals, and a general risk of side effects is known. Severe side effects such as agranulocytosis and liver failure are in general considered rare, but for the use of ATDs in pregnancy there is an additional concern about teratogenic adverse effects. The initial concern emerged from case reports and case series half a century ago and more recently, large observational studies have added new evidence and quantified the risk of birth defects associated with different types of ATDs. The findings that all clinical available ATDs have been associated with birth defects challenge the clinical recommendations on the treatment of hyperthyroidism in an around the early pregnancy period and have led to considerations on the timing and dosage of treatment as well as the role of maternal thyroid function per se.