Topological Properties and Spatial Organization of Villous Capillaries in Normal and Diabetic Placentas

Abstract

Spatial arrangement and complexity of the capillary bed of placental terminal villi were analyzed in 9 normal and 11 diabetic placentas. Specimens were taken by systematic random sampling, fixed and stained in toto, and embedded in paraffin. Fifteen fields of view were sampled systematically from 120-µm-thick sections of specimens and examined using a confocal laser scanning microscope. Series of thin optical sections of terminal villi and their developmental forms were recorded by the confocal microscope and used as initial data for three-dimensional visualization of the spatial arrangement of villous capillaries. Vascular topology and branching were studied by focusing through the villus, making a schematic drawing of the villous capillary bed and counting redundant capillary connections. It was found that the basic arrangement of villous capillaries is similar in both normal and diabetic placentas. Nevertheless, the proportion of simple forms of the capillary bed without redundant connections is significantly higher in normal placentas and the mean number of redundant connections per villus is significantly higher in diabetic placentas. It is concluded that both the longitudinal growth and branching of capillaries contribute to the increase in the placental capillary bed in late gestation and that the capillary bed of diabetic villi is more complicated due to more intense capillary branching.

Vascular endothelial cadherin and �-catenin in human fetoplacental vessels of pregnancies complicated by Type 1 diabetes: associations with angiogenesis and perturbed barrier function

“…Since some of these pregnancies may have included pre-gestational Type 2 diabetes patients, further investigations on gestational diabetes are required to resolve the apparent discrepancies. Recently, a study using three-dimensional visualisation techniques has reported increased longitudinal growth of fetoplacental vessels and enhanced branching angiogenesis in gestational diabetes [49].…”

The Morphology of Villous Capillary Bed in Normal and Diabetic Placenta

“…These schemes of various forms of villous capillary beds were statistically analyzed, and mean numbers of redundant connections per villus and ratios of villous capillary beds without and with redundant connections were finally summarized in table 1. The results achieved in control placentas were significantly different from results achieved in placentas from pregnancies complicated by both gestational diabetes (Jirkovská et al, 2002) or type 1 diabetes (unpublished data). On the other hand, the results obtained in diabetic groups showed no significant differences.…”

“…15). The used methods of confocal microscopy and 3D reconstruction enabled us also to demonstrate that placental villous capillaries grow by elongation as well as by sprouting of pre-existing capillaries until term (Jirkovská et al, 1998;Jirkovská et al, 2002, Karen et al, 2003Jirkovská et al, 2008). This finding challenged the hypothesis, expressed by some authors, that placental angiogenesis shifts from the sprouting to the elongating angiogenesis after the 25th week of gestation Mayhew, 2002 b).…”

Placental virtual biopsy: 3D-US hemodynamics of normal pregnancy versus gestational diabetes

“…For this reason, the evaluation of conventional funicular-Doppler does not have a predictive value in gestational diabetes. However, placentas in this type of pregnancies present hystological alterations, showing a significant decrease of the number of blood vessels [1][2][3] . The search for placental hemodynamic markers may be a good method for the prediction of the metabolic condition of these fetuses, no matter the degree of oxygenation, and for establishing an early prognosis [4][5][6][7] .…”