Pregnancy and autoimmune thyroid disease.

Pregnancy has profound effects on the course of Graves' disease and Hashimoto's thyroiditis. Understanding of this interrelationship may clarify the role of the numerous immunologic gestational alterations that facilitate survival of the fetal allograft. Also, it should provide a more rational basis in the management of Graves' hyperthyroidism during pregnancy. Epidemiologic data indicate that screening for thyroid dysfunction appears justified in women in the postpartum period. The natural history of the postpartum thyroiditis syndrome remains to be fully evaluated, but the evidence indicates thyroid abnormalities can still be found in many patients several years after onset. Accordingly, the importance of follow-up cannot be overemphasized.