Pitfalls in prenatal diagnosis of unusual congenital abdominal wall defects.

We report three cases of unusual skin covered abdominal wall defects not accurately diagnosed by prenatal sonography. An associated omphalocele was recognized in two but misinterpreted as a giant omphalocele in one. Suspicious sonographic features--an enlarged abdominal circumference, irregular laxity of the abdominal--may be clarified by MRI.