Thyroid Storm and Neonatal Hyperthyroidism

Abstract

Thyroid storm during pregnancy is rare but put the mothers and the neonates in a critical condition that can culminate to high morbidity and mortality and need to be diagnosed and managed appropriately. Clinical findings of thyroid storm are exaggerated form of the usual symptoms of hyperthyroidism. The diagnosis of thyroid storm is based upon clinical and laboratory findings. The first-line therapy in treating thyroid storm consists of using thionamides (Methimazole, Propylthiouracil), which halt new thyroid hormone production; PTU has an additional benefit of reducing the peripheral conversion of T4 to T3 which is a more favorable treatment option. New thyroid hormone synthesis can be blocked by adding nonradioactive iodine in the form of SSKI or Lugol’s solution. General supportive measures, such as antipyretic drugs, and cardiovascular monitoring, maintaining normal oxygen level, are also important. The perceived underlying cause of thyroid storm should be treated.

Natural course of neonatal hyperthyroidism shows that it usually is self-limited, but it can be severe, even life-threatening, and may have deleterious effects on neural development. Neonatal hyperthyroidism can occur in babies whose mothers have active Graves’ disease or who are born to women with a stimulatory TSHR-Ab associated with Hashimoto thyroiditis due to trans-placental passage of the maternal stimulatory TSH receptor antibody; it also can occur in infants of women who do not have active disease during pregnancy but has a history of Graves’ hyperthyroidism treated either with radioactive iodine or thyroidectomy previously and the level of stimulatory TSHR-Ab remained high during pregnancy. Elevated FT4, TT4, and total T3, with low TSH, are infamous of neonatal Graves’ disease. Thionamides are the drug of choice for controlling the disease. A beta-adrenergic blocker can be added to control symptoms of neuromuscular and cardiovascular hyperactivity. Iodine can be given to inhibit thyroid hormone release in severe form of the disease. A multidisciplinary team approach is critical for management of thyroid storm during pregnancy in order to successfully give the patients who suffer from thyroid storm all possible diagnostic and therapeutic options.