CHAOS in the mirror: Ballantyne (mirror) syndrome related to congenital high upper airway obstruction syndrome.

In the mirror syndrome, maternal edema mirrors fetal edema. The pathogenesis is unknown. The most common etiologic associations are rhesus isoimmunization, twin-twin transfusion syndrome, and viral infections. Less than 10% of reported cases are associated with congenital anomalies. We report a case due to congenital laryngeal stenosis, which also caused congenital high airway obstruction syndrome (CHAOS), characterized by pulmonary hyperplasia and edema or anasarca, related to airway abnormality. The fetal manifestations of the mirror syndrome and CHAOS overlap, but occurrence of the two in the same patient does not seem to have been reported.