Placental morphometry using a computer assisted measuring programme: reference values for normal pregnancies at term.

Using the principle that the human placenta is anatomically composed of fetomaternal flow units, we developed a computer-assisted measurement programme capable of recording complex histometric data about the characteristics of the maturation and structural differentiation of resorption villi, as well as subjecting the results to simultaneous statistical processing. Using 42 placentas obtained after normal pregnancies, reference values were derived for the five primary geometrical and six further arithmetical parameters. From these findings, we also calculated the total resorption villi surface area, the proportion of this surface area occupied by epithelial plates, and the resorption-villi surface are relative to the birth weight of the child. Our findings are compared with other available results, and the reasons for discrepancies between previously published measurements are discussed.