NB- Absence of musculature in an area of the diaphragm allows abdominal viscera to bulge into the thorax. The presence of viscera within the thorax may be recognized on ultrasound, but diagnosis of eventration requires visualization of the diaphragm. The abdominal circumference usually remains normal, and the stomach bubble may retain its normal position.
Bilateral eventration has been reported with toxoplasma and cytomegalovirus infections.