Microscopic investigation of villi from chorionic villous sampling

The aim of the present study was to investigate the morphology of cytogenet ically normal chorionic villi from chorionic villous sampling (CVS) specime ns. This information can serve as a reference for morphological investigati on of cytogenetically abnormal CVS specimens. We were also interested in an y relationship between chorionic villous architecture and the outcome of pr egnancy, In a reference group (n = 94, normal karyotype and ongoing pregnan cies), we observed a considerable variation in villous diameter (range 116- 377 mu m) and vascular density (range 0.5-6.7 vessels/villus) and a high in cidence of morphological criteria, classically mentioned in relation to chr omosomal or other abnormalities, such as: fibrinoid deposition (74.5%), tro phoblastic layer degeneration (3.2%) and abnormal proliferation (7.4%), ava scular villi (54.2%), stromal oedema (55.3%), trophoblastic inclusions (23. 4%) and fibrosis (23.4%), In the cytogenetic abnormal group (n = 10), neith er the diameter nor the vascular density of the villi differed from the val ues observed in the reference group. In the reference group, we only observ ed a tendency for larger birthweights in relation to respectively larger an d more vascularized villi. It is concluded that in CVS specimens, chorionic villous architecture and morphological criteria do not have any clinical r elevance, neither do they have any important predictive value.