Oligohydramnios and fatal pulmonary hypoplasia without amnion nodosum

Two cases of fatal pulmonary hypoplasia associated with hydrorrhea gravidarum are presented. Amnion nodosum was present in one case but not the other. The pathogenesis of amnion nodosum is reviewed, and the clinical implications of this pathologic finding are discussed in relation to whether the underlying pathology is renal agenesis or amniorrhea.