There are international protocols for the management of hypothyroidism induced by autoimmune thyroid disease during pregnancy. In this descriptive study, we analyzed the implementation of international protocols regarding these pathologies, in local clinical practice. Analyzing the cases admitted to the Obstetrics and Gynecology department of Bucharest University Emergency Hospital on a period of 55 months, we identified the pregnancies with autoimmune hypothyroidism treated with Levothyroxine (LT4). We determined the prevalence of specific immunological markers for autoimmune hypothyroidism in pregnant women, we analyzed whether they are associated with distinct clinical phenotypes and ultrasound characteristics, and also, we evaluated the treatment of choice. Measurement of thyroglobulin antibodies, thyroid peroxidase antibodies, Thyroid-Stimulating Hormone, free fractions of Triiodothyronine and Thyroxine with substitute treatment instituted early (in the first 2 weeks postnatal) determine the normalization of cognitive development, especially in areas known for iodine deficiency, including Romania.