Autoimmune thyroid disease and pregnancy

The natural course of autoimmune thyroid disease is profoundly altered by both the establishment and cessation of pregnancy. Despite much investigation, however, we understand neither the initiation of thyroid autoantibody production nor its alleviation by pregnancy. While a variety of thyroid autoantibodies are now easy to monitor, the innocuous placental passage of hTg and microsomal antibodies has indicated their inability to initiate the disease process alone. In contrast, antibodies to the follicular cell membrane are able to initiate neonatal thyroid dysfunction and are, therefore, likely to be important in the etiology of the disease. The fascinating postpartum thyroid syndromes, which are being increasingly recognized as transient disease, indicate that autoimmune thyroid disease can be suppressed in many individuals. The mechanisms of such suppression offer important areas of future investigation.