Thyroid Diseases in Pregnancy

Thyroid disorders are generally more frequent in females than in males., in particular during the child-bearing period. Not surprisingly, therefore, these disorders are common clinical problems in pregnant women. Management of thyroid disease in pregnancy involves specific problems, primarily but not exclusively related to the significant changes in maternal thyroid economy during pregnancy. These changes, for instance, make the non-pregnant population reference ranges of thyroid function parameters invalid for pregnant women. For this reason, the use of gestational and trimester-specific reference ranges is strongly recommended for interpreting thyroid results during pregnancy. In addition, the natural course of some thyroid diseases may be affected by pregnancy. In fact, some thyroid diseases may become evident or worsen during pregnancy, whereas other conditions such as Graves’ disease usually improve during pregnancy and relapse in the postpartum period. Finally, pregnancy imposes some therapeutic limitations, mostly related to possible effects of drugs used on fetal thyroid function. Because of these specific considerations, the management of pregnant women with thyroid disease requires special care, bearing in mind that both maternal thyroid disease per se and related treatments may adversely affect the newborn’s health.