Background: Congenital High Airway Obstruction Syndrome (CHAOS) is an uncommon anomaly. Prenatal ultrasonography allows a prenatal diagnosis to prepare for immediate surgical correction at birth. If the obstruction is severe and a correct therapeutic approach is not planned, CHAOS can cause neonatal death shortly after delivery from a potentially surgically correctable lesion.Case report: This neonate died unexpectedly shortly after delivery due to CHAOS. Ultrasonographic findings of enlarged echogenic lungs, dilated airways distal to the obstruction, flattened or inverted diaphragms, or ascites were absent. This was due to a type-II laryngeal-atresia and a type-C esophageal-atresia, with a resultant distal fistula that allowed intrauterine decompression of the fluid in the lungs.Conclusions: The absence of prenatal ultrasonographic findings of CHAOS may be due to a lower fistula between respiratory and gastrointestinal tracts. This set of associations may not be a surgically correctable cause of CHAOS.
Keywords: congenital abnormalities; congenital high airway obstruction syndrome; infant autopsy; larynx atresia; pathology.