Does hypercapillarization influence the branching pattern of terminal villi in the human placenta at high altitude?

This study tests the hypothesis that exposure of the placenta to hypobaric hypoxia at altitude results in an altered branchingpattern of the villous tree. Histological material from 20 term placentae delivered at altitudes over 3000 m was compared with matched controls from 500 m. Estimates of the mean star volume of intermediate and terminal villous domains were 1.40 × 10 6 μm 3 (s.d. 0.63) in the high altitude group and 1.90 × 10 6 μm 3 (s.d. 0.34) in the controls (F=9.07, P