Neonatal Thyrotoxicosis.

Neonatal thyrotoxicosis (hyperthyroidism) is less prevalent than congenital hypothyroidism; however, it can lead to significant morbidity and mortality if not promptly recognized and adequately treated. Most cases are transient, secondary to maternal autoimmune hyperthyroidism (Graves disease [GD]). This article summarizes recommendations for screening and management of hyperthyroidism in both the fetal and neonatal periods, with a focus on neonatal thyrotoxicosis secondary to maternal GD.