Scanning Electron Microscopic Findings of Human Chorionic Villi

The surface ul rastructure of the human chorionic villi was examined by means of a scanning wlwctron microscope, Model JSM-S1.Samples studied were normal chorionic villi from each three trimesters, and also from hidatidiform moles. They were all coated with carbon and gold. Results obtained were followings : (1), in samples from the first trimester, chorionic villi as a whole appeared as branches or cactus. Stumps and braches of chorionic Villi were rather uniformly covered with microvilli, compared with those from late timesters, which were well maturated chorionic stumps. (2), in ones from the second and third trimesters, though the general appearance of chorionic villi was similar to that from early trimester, distribution of microvilli was more uneven, and they were rather short and not as well grown as those from the first trimester. (3), in hidatidiform moles, miclovilli were more sparse and edematous than the normal ones.