[Thyroid stimulating antibodies in pregnant women with Graves' disease and neonatal thyrotoxicosis]

Thyroid stimulating antibodies (TSAb) are thought to be involved in the initiation of Graves' disease, and thyrotoxicosis in the neonatal period is often caused by TSAb passing the placental barrier. We wanted to evaluate measurement of TSAb levels as a possible predictor of neonatal thyrotoxicosis in pregnant patients with Graves' disease. We retrospectively evaluated 18 consecutive pregnant patients with Graves' disease. In 16 patients TSAb were measured in early pregnancy, six had increased values. In 14 of 18 patients normal values were found in late pregnancy and none of the children developed neonatal thyrotoxicosis. Two patients had greatly elevated TSAb values, and their children had neonatal thyrotoxicosis. Two patients had slightly elevated TSAb levels and delivered normal children. We conclude that all pregnant patients with an actual or a history of Graves' disease, should have measured TSAb. High TSAb values in late pregnancy indicate a considerable risk of neonatal thyrotoxicosis.