Thyroid Disease in Women

Thyroid disorders occur more commonly in women than in men. This gender difference can be accounted for, in part, by the autoimmune nature of many thyroid disorders. Autoimmune diseases occur more frequently in women, presumably secondary to the effects of sex steroids on the immune system. 1 , 19 Although incompletely elucidated, estrogen and progesterone appear to modulate the differentiation and maturation of lymphocytes as well as the induction of the autoimmune response. 1 Many autoimmune diseases ameliorate during pregnancy, however, which is a high estrogen and progesterone state, 13 , 19 and exacerbate in the postpartum period. In addition, autoimmune postpartum thyroid dysfunction occurs frequently, even in women without a previous history of thyroid disease. It has been hypothesized that immune inhibitory cytokines, produced by the mother, fetus, or placenta, inhibit the immune response during pregnancy. 19 , 38 The subsequent decrease in these inhibitors in the postpartum period allows for exacerbation or onset of autoimmune disease. Therefore, the relationship between sex steroids and the immune system appears to be complex and is potentially subject to further regulation by local cytokines. There are also unique changes in thyroid function during pregnancy, which are nonautoimmune related. Finally, nodular thyroid growth occurs frequently in both premenopausal and postmenopausal women. Thus, this article reviews the current information on the pathophysiology and treatment of thyroid disorders that are common in women.