Introduction: Thyroid autoimmunity is very frequent in women of reproductive age and is associated with many adverse pregnancy outcomes; also, diabetes mellitus in pregnancy, of any type, is associated to many complications. In type 1 diabetes, the prevalence of thyroid autoimmunity is higher than in healthy population. Instead, the association of thyroid autoimmunity with other types of diabetes is less clear; however, there are some studies claiming that the prevalence is higher in gestational diabetes too. Poor data about type 2 diabetes in pregnancy are available. It is also unclear how diabetes and thyroid function influence each other and if levothyroxine therapy is necessary in pregnancy with positive autoimmunity but normal thyroid function.
Materials and methods: The aim of this article was to find in the literature studies on thyroid autoimmunity in different types of diabetes in pregnancy, in order to detect any difference in prevalence. Data were found through pubmed database from 1990 to 2013.
Conclusions: Several studies found a higher prevalence of thyroid autoimmunity in GDM compared to healthy controls; therefore it would be appropriate to extend screening for thyroid diseases to women with GDM. More studies are needed on the possible requirement of therapy for thyroid autoimmunity when the function is normal.