Prenatal ultrasonographic detection of the tracheal atresia sequence.

We report a rare case of tracheal atresia, without fistula, in a 19 weeks' female fetus. The abnormality was detected by prenatal ultrasonography, which demonstrated a bilateral and uniform hyperechogenicity and enlargement of the lungs, associated with ascites and moderate oligohydramnios. We suggest that oligohydramnios may be helpful in distinguishing the upper respiratory tract obstruction from congenital cystic adenomatoid malformation of the lungs, type III. A morphometric study revealed a three-fold more dense pulmonary vasculature in comparison with two control cases of the same gestational age. The pathological finding of pulmonary and vascular hyperplasia as well as the pathophysiology of the syndrome are discussed.