Prenatal diagnosis of fetal hyperthyroidism using funipuncture.

Women with Graves disease who are euthyroid as a result of ablative therapy still produce thyroid-stimulating antibodies that can cross the placenta. The fetuses of such patients are at risk of hyperthyroidism. We found that fetal blood sampling for the measurement of fetal endocrine function was useful in two patients for both diagnostic and therapeutic purposes. It may be especially helpful for situations in which maternal and fetal endocrine functions are dissimilar.