A stereologic study on the thickness of the trophoblastic layer and its regional variation in the human term placenta

A new stereological method was applied to estimate the average thickness of the trophoblastic layer in chorial villi from different regions of the human term placenta. Statistically significant differences were demonstrated among the 5 regions considered. The results suggest that the thickness of the trophoblastic layer is related to the pO2 gradient in the intervillous space blood.