Abstract

Two patients with neonatal Graves's disease are reported. One of them had a delayed onset because of suppression of the fetal thyroid gland by antithyroid drug taken by the mother during pregnancy. Thyroid-stimulating immunoglobulins (TSAb), measured by a receptor assay, were present in both babies when they were thyrotoxic, and also in their mothers. TSAb were undetectable in both babies 1 year after birth. This strongly supports a pathogenetic role of TSAb in this condition through transplacental transfer of maternal TSAb.