Hashitoxicosis during pregnancy in a woman with established hypothyroidism. Clinical case report

Abstract

Introduction: The term 'hashitoxicosis' is used to describe an autoimmune thyroid disease overlap syndrome of Graves' and Hashimoto's disease. Clinical case: 23-year-old woman diagnosed with Hashimoto's hypothyroidism, attended endocrinology evaluation at 19 weeks of gestation due to altered thyroid hormones and elevated anti-TSH receptor antibodies, compatible with Graves' disease, in the presence of hyperthyroidism symptoms. She received antithyroid pharmacological therapy, in postpartum control she showed a return to hypothyroidism. Discussion: During pregnancy, changes occur in the biochemical parameters of the thyroid, being essential the differential diagnosis of Graves' hyperthyroidism during pregnancy, which is confirmed with the presence of positive anti-TSH receptor antibodies. The use of antithyroid pharmacological therapy with propylthiouracil or methimazole depends on the week of gestation. Conclusion: The transformation of spontaneous autoimmune hypothyroidism to Graves' disease during pregnancy is rare, its follow-up and treatment are not defined, so close control is required.