Thyroid Diseases and Pregnancy

Thyroid diseases in pregnancy must be recognized as a specific challenge for the clinician. Any pregnancy is causing alterations in thyroid hormone metabolism which have to be differentiated from pathologic states of thyroid function. Any thyroid disease of the mother with disturbances in the functional state of the gland could induce an adverse influence on the course of pregnancy. Furthermore, it can be associated with adverse consequences on fetal development. Especially hypothyroidism has to be avoided during pregnancy due to a danger of affected neurocognitive development of the offspring. Yet also maternal hyperthyroidism can lead to impairments in the course of pregnancy and to fetal thyroid dysfunction. Further clinical attention should be given to thyroid autoimmunity. There is a clear relationship between autoimmune thyroid disease and decreased fertility and an increase in the rate of spontaneous miscarriages. Furthermore, it displays an increased risk for the manifestation of postpartum thyroiditis. The management of nodular thyroid disease and malignancy does not differ from that of nonpregnant women/patients. Thyroid scintiscan and radioiodine therapy must be avoided during pregnancy and lactation. This review deals with the broad variety of thyroid disorders and function disturbances during and after pregnancy. All described diagnostic and therapeutic procedures are based upon the recent Clinical Practice Guideline of the Endocrine Society published in August 2007.