Congenital absence of the lumen of the larynx. Laryngeal atresia is a rare condition. If the laryngeal opening fails to develop, fluid secreted by the lungs cannot be expelled. In a fetus with laryngeal atresia, the lungs are either normal or hyperplastic, not hypoplastic. Mortality is reported as 100%. At obstetric US examination, views of the fetal neck demonstrate a dilated trachea filled with trapped fluid. Views of the fetal chest show enlarged, hyperechoic lungs, with dilated fluid-filled bronchi. Fetal ascites is usually present. [from
HPO]