def: The diaphragm normally projects up into the thoracic cavity. In the presence of malformations such as enlarged lungs, the diaphragm may appear abnormally flat or even everted (with the middle of the diaphragm projecting downwards into the abdominal cavity).
New term request Prenatal ultrasound: diaphragm flattened (elthat_101002181953): Downward displacement; eversion of diaphragm included UMLS: 0743169