The antenatal diagnosis of diaphragmatic anomalies.

In an evaluation of eight fetal diaphragmatic anomalies a number of suggestive antenatal ultrasound findings were identified. The feature most suggestive of a posterolateral hernia (foramen of Bochdalek) is malposition of the heart. Peristalsis of chest contents or movement of abdominal contents into the chest on inspiration are more specific findings. Absence of an intra-abdominal stomach, a small abdominal circumference, and a cystic or solid mass in the chest are suggestive but not specific. It may be difficult or impossible to distinguish a posterolateral diaphragmatic defect from the much less frequent eventration of the diaphragm. An anteromedial defect of the diaphragm (foramen of Morgagni) presented as an intrathoracic anterior solid mass and should be considered in the differential diagnosis of an anterior chest mass. Although all three types of defects are frequently associated with additional anomalies, severe pulmonary hypoplasia is not a complication of eventration or anteromedial defects.