Aortic thrombosis in the newborn period.

Three cases are reported in which thrombi were found in the aorta at postmortem. In each case the thrombus had originated within the ductus arteriosus. We believe that in recent years the attention paid to the presence of indwelling cannulae as a cause of embolic phenomena in the newborn period has led to a reduction in emphasis on the importance of the ductus in this field. We think that the ductus should still be regarded as an important source of some emboli.