[Thyroid nodule and cancer in pregnant women]

Most thyroid nodules discovered during pregnancy are benign. In this article, we propose a pragmatic attitude for the diagnosis and treatment of such nodules, insisting particularly on the importance of thyroid echography and fine needle aspiration. For women who have successfully been treated for thyroid cancer before pregnancy, we discuss the adaptation of thyroxine substitution when they become pregnant, the obstetrical and fetal risks (spontaneous miscarriage, fetal abnormalities of the thyroid gland and others), and also potential later risks for the child, in relation with previous radioactive iodine administration to the mother. Finally, we evoke more difficult questions, such as the rare instances in which thyroid cancer is discovered during pregnancy, pregnancy occurring during the months immediately following radioiodine treatment, and exceptional cases where therapeutic radioiodine was inadvertently given during pregnancy.