Category: obstetric USG, Region: Thorax-Trachea, Plane: Coronal
This is a rare case of congenital high airway obstruction syndrome (CHAOS) of a fetus diagnosed on a routine antenatal ultrasound scan at 19 weeks gestation. Pre-natal sonogram revealed characteristic features of enlarged and echogenic fetal lungs, inversion of diaphragm, and fetal ascites. Detailed sonographic evaluation revealed significantly dilated tracheobronchial tree. Polyhydramnios and placentomegaly were present. Fetal MRI confirmed th sonographic findings and accurately located the level of obstruction at the larynx. A definitive antenatal diagnosis of CHAOS was made. Findings were confirmed on aborted fetus on sonography and X-ray contrast studies of the upper airway. Fetal autopsy confirmed the underlying cause of laryngeal obstruction being subglottic stenosis with the presence of elliptical cricoid ring in our case. Why this case should be published: Ours is the first case to demonstrate the role of post mortem contrast x-ray studies in fetal airways to confirm the prenatal diagnosis of CHAOS. Findings of antenatal imaging are correlated well with post mortem fetal sonogram, X ray contrast studies of upper airways and fetal autopsy findings.