Thyroid physiology and common diseases in pregnancy: review of literature.

Thyroid diseases are common during pregnancy and an adequate treatment is important to prevent adverse maternal and fetal outcomes. Subclinical diseases are very frequent but not easily recognized without specific screening programs. In this article we try to summarize the knowledge on the physiologic change of the thyroid and pathological function during pregnancy; we also try to describe the best way of diagnosis and treatment of thyroid dysfunction.