[Functional morphometry of the villous surface of the mature human placenta]

In 22 placentas of spontaneous delivered new-borns after a normal course of pregnancy and delivery the entire surface of resorption of the placenta was determined by means of multiple macroscopic and microscopic parameters. It could be demonstrated that the placental tissue is subject to a homogeneous shrinking process during the usual process of histologic preparation. The influences of fixation and histologic preparation are strongly marked. They have to be taken in consideration when the total villous surface is calculated. In the present study the distribution pattern of stem villi, immature villi and terminal villi in the total volume of villi was studied in representative histologic sections from the periphery of placentones. In this area also the content of intervillous fibrin and the quota of syncytial knots in the placental tissue was determined. Our average value for the total villous surface can serve as a standard for planned studies in placentas of high risk pregnancies.