MANAGEMENT OF THYROTOXICOSIS: PRECONCEPTION, PREGNANCY, AND THE POSTPARTUM PERIOD.

OBJECTIVE: To review the diagnosis and management of thyrotoxicosis in women who are preconception, pregnant, and in the postpartum period. METHODS: Literature review of English-language papers published between 1980 and 2018. RESULTS: Overt thyrotoxicosis occurs in 0.2% of pregnancies and subclinical thyrotoxicosis in 2.5%. Hyperthyroidism in women of childbearing age most frequently is caused by Graves disease (GD). Gestational thyrotoxicosis, transient human chorionic gonadotropin (hCG)-mediated hyperthyroidism, may develop in the first trimester. In the first year following delivery, postpartum thyroiditis, which frequently includes a thyrotoxic phase, occurs in 5% of women. Hyperthyroidism from nodular autonomy is uncommon in women of childbearing age. It is essential to understand the underlying etiology for thyrotoxicosis in order to recommend appropriate treatment. Gestational thyrotoxicosis requires supportive care, without antithyroid drug therapy. GD may be treated with antithyroid drugs, radioactive iodine, or thyroidectomy. Pregnancy, plans for pregnancy, and lactation have important implications for the choice of GD treatment. When thyrotoxicosis presents following delivery, postpartum thyroiditis must be differentiated from GD. CONCLUSION: The diagnosis and management of thyrotoxicosis in the peripregnancy period present specific challenges. In making management decisions, it is essential to weigh the risks and benefits of treatments not just for the mother but also for the fetus and for breastfed infants. A team approach to management is critical, with close collaboration among endocrinologists, maternal-fetal medicine specialists, and neonatologists. ABBREVIATIONS: GD = Graves disease; hCG = human chorionic gonadotropin; MMI = methimazole; PPT = postpartum thyroiditis; PTU = propylthiouracil; T3 = triiodothyronine; T4 = thyroxine; TBG = thyroxine-binding globulin; TRAb = TSH receptor antibody; TSH = thyroid-stimulating hormone.