The pathology of intrauterine thyrotoxicosis: two case reports.

The autopsy findings are described in two infants of hyperthyroid mothers in whom the clinical symptomatology, laboratory data, and autopsy findings strongly suggested intrauterine thyrotoxicosis secondary to transplacental thyroid-stimulating immunoglobulin. Documented intrauterine thyrotoxicosis is extremely rare, and we believe these to be the first detailed pathologic descriptions of the entity. Autopsy findings included slim habitus, massive thyromegaly, hypertrophic cardiomegaly, congestive visceromegaly, pulmonary hypertension, adenopathy, and prominent amniotic fluid aspiration. Both cases illustrate the positive contribution that a carefully performed autopsy, even in the severely macerated stillborn, can make toward better understanding of intrauterine disease.