[Study on the stereo-architectural changes in human placental villi of toxemia of pregnancy].

Architectural changes in placental villi in clinical types of toxemia of pregnancy which were divided into four groups according to the main maternal symptoms (hypertension: H type, proteinuria: P type, PH type and IUFD) were studied by scanning electron microscopy and computerized image analysis of serial paraffin step sections. Furthermore plastic casts of villous capillaries were compared and changes in endothelial cells of villous capillaries were observed by transmission electron microscopy. 1) Scanning electron microscopy showed characteristic differences between P type cases and H type cases. Terminal villi were markedly reduced in number and showed few branches especially in P type cases, whereas in H type cases slender terminal villi were observed. The surface structure showed rough degenerative microvilli in H type cases and slender long microvilli in P type cases. 2) Average diameters of terminal branches estimated by image analysis were as follows: Normal cases: 24.8 mu, P type: 23.1 mu, H type: 17.9 mu, PH type: 17.7 mu, IUFD: 13.8 mu. The reduction in the number of intermediate villi in cases of toxemia of pregnancy was about 58% of that of normal cases. 3) Plastic casts of villous capillaries emphasized these changes in each type. 4) Swelling of the endothelial cell into the capillary lumen was observed and an increase in the number of filamentous structures in the cytoplasm of endothelial cells was detected by transmission electron microscopy.