Placentarzotte bei Schwangerschaftstoxikose und fetaler Erythroblastose im fluorescenzmikroskopischen Bilde

Morphology of placental villi after premature delivery and its clinical relevance

Based on a new concept of maturation of the placental villous tree and its disorders (synchronous and asynchronous immaturity, asynchronous maturity, hypermaturity, and terminal villi deficiency) we studied the possible effect of the placental villous tree on the premature onset of labour. In mature normal neonates irregular and asynchronous villous patterns were found in 50% of cases. In prematurely delivered neonates, only 33% of the corresponding placentas show synchronous immature villous patterns. Uterine bleeding in the first trimester was associated with a 42% of incidence of premature maturation of the villous tree. These findings strengthen the idea that hormonal imbalance in early pregnancy influenced villous development. In "prematurity without recognizable cause" there was a higher percentage of villous maldevelopment (33%) than that previously described in the literature. In severe pre-eclampsia combined with premature onset of labour, 60% of our cases showed hypermaturity of the villous trees. Synchronous immaturity was reduced to 15%. We conclude, that even a rather rough definition of the histological features of placental villi is sufficient to produce numerous correlations between clinical events preceding premature delivery and placental structure. So the influence of placenta on the premature onset of labour needs more attention.

[Problems of distinction of normal, arteficial and pathological structures in mature human placental villi. III. Morphometric studies in rhesus incompatibility (author's transl)]

Sections of human placental villi which were up to 80 micrometer in diameter were examined light microscopically and morphometrically. The villi were obtained by taking an aspiration biopsy of the attached placenta from 20 normal patients at term and from eight patients delivered at or before 37 weeks because of varying degrees of rhesus incompatibility. The distribution of three histological types of villi was determined. The intermediate villi from patients with erythroblastosis showed an increase in number and volume matching the severity of the disease. The intermediate villi also showed an increase in the amount of cytotrophoblasts, in the amount of materno-fetal diffusion surface area, in the thickness of syncytium, and in the number of Hofbauer cells. The terminal villi were not affected by erythroblastosis and the mature end villi showed a relative decrease in number. To obtain these results an optimal fixation technique was required.

An ultrastructural study of the placenta in materno-fetal rhesus incompatibility

An electronoptical study has been made of eleven placentae from cases of materno-fetal rhesus incompatibility. The characteristic findings are focal, but sometimes quite extensive, syncytial necrosis, retention of normal pinocytotic and secretory activity in the non-necrotic syncytiotrophoblast, cytotrophoblastic hyperplasia, thickening of the trophoblastic basement membrane, immature-type endothelial cells in the fetal villous vessels and thickening or lamination of the capillary basement membranes. The pathogenesis of many of these chantes is not clear but there is no evidence that they are immunologically mediated. It is suggested that the syncytial necrosis may be due to narrowing of the intervillous space as a result of increased villous size, that the cytotrophoblastic hyperplasia is a response to the syncytial damage and is responsible for the changes in the trophoblastic basement membrane and that the fetal capillary changes are indicative of endothelial cell damage due, possibly, to fetal anaemia. Despite the damage suffered by the placenta in materno-fetal rhesus incompatibility there is little evidence of impaired functional efficiency.

[Quantitative investigations of the human placenta under normal conditions and in case of preeclampsia correlated to the human placenta-lactogen blood-level in the last third of pregnancy (author's transl)]

Thirty-two human placentas from normal and from pregnancies complicated by preeclampsia in last third of gestation were morphologically and morphometrically examined and correlated with human placenta-lactogen blood-level. HPL was determined by the radio-immunoassay (Carbon-Dextran-method). HPL-values, placenta villous surface, the weight of the newborn and placenta showed significant correlation. The placentas were classified according to the morphologic degree of severity (placenta-morphological-index) and compared to preeclamptic index (Goecke) and HPL-values. The results showed correlation between the studied datas according to the severity of preeclampsia. The significance of these results is discussed.