Quantitative study of placental villi in trisomy by analytical morphometry.

Objective: To assess the relationship between morphologic features of placental villi and the occurrence of trisomy.

Study Design: We selected 9 placentas with genetically diagnosed trisomy 21 and 6 normal placentas of matched gestational age. The 150 selected villi underwent a morphometric study using the Shape Analytical Morphometry system, availing itself of an ordinary section to study dimensions and of a specific section to study the shape. The analytic morphometric procedure for shape analysis consisted of 3 steps: upper degree polynomial equations, Fourier analysis and parabolic fitting.

Results: Trisomic villi showed bigger size and a more asymmetric and irregular shape than did normal villi.

Conclusion: We believe that this method can provide valuable information and that further studies are needed to analyze more cohorts of pathologic villi, thus providing a complete pattern of morphologic aberrations related to each placental disease.