Pseudoomphalocele: pitfall in fetal sonography.

Compression of the fetal abdomen between the walls of the uterus or placenta can result in an appearance that mimics that of omphalocele on sonography. This may be caused by oligohydramnios or by a transient compression of the fetal abdomen with a normal amount of amniotic fluid. Four cases of pseudoomphalocele and one case of true omphalocele are presented.