The question of a helminthic cause of preeclampsia

Two recent reports have suggested that wormlike structures characteristic of helminths are associated with preeclampsia. We identified these vermiform structures in toluidine blue O-stained venous blood smears from four women with preeclampsia, cord blood taken at delivery of three of their neonates, and venous blood from five control subjects without preeclampsia and from five healthy beagle dogs. The structures, which had diameters between 30 and 670 microns, could not be concentrated by passing the blood through a 12-microns filter, yet they could be demonstrated in stained smears prepared from blood that had been filtered. We conclude that these structures are not helminths; they are most likely artifacts of staining.