Thyroid diseases in pregnancy other than Graves' disease and postpartum thyroid dysfunction

Second to diabetes mellitus, thyroid diseases are the most common endocrino pathies seen in pregnancy. Furthermore, thyroid diseases may manifest in th e postpartum period, affecting between 5 and 10% of women. Prepregnancy cou nseling is an important component in the care of women with thyroid disease . It is of paramount importance to achieve euthyroidism before conception; the potential complications of thyroid dysfunction and drug therapy during pregnancy should be discussed at length with the future parents. Thyroid ec onomy is influenced in pregnancy by different factors, among them human cho rionic gonadotropin (hCG), changes in thyroxine binding globulin, and by io dine demands. High levels of hCG or alterations in its structure may stimul ate the maternal thyroid gland, affecting not only the interpretation of th yroid tests (as seen in twin pregnancies) but producing clinical or subclin ical hyperthyroidism (Hydatidiform mole and hyperemesis gravidarum). Hypoth yroidism may be diagnosed in pregnancy for the first time; women on chronic thyroid therapy may need an increase in the dose of thyroid medication bec ause of the increased demands during pregnancy. Rapid correction of hypothy roidism is imperative to prevent maternal and fetal neonatal complications such as pregnancy induced hypertension (PIH), prematurity, and in some case s fetal distress, The natural history of thyroid cancer is not affected by pregnancy The work up and treatment of thyroid nodules may be postponed unt il after delivery without jeopardizing maternal health. If surgery is conte mplated, it is relatively safe to perform it before 24 weeks of gestation. The incidence of spontaneous abortions is in creased in women with chronic thyroiditis, as is the development of postpartum thyroiditis. A team approa ch in the care of women with thyroid disease should include the combined ef forts of the obstetrician, endocrinologist, and neonatologist.