Increase of segments of elastic-type blood vessel walls in fetal placental stem villi during pre-eclampsia at term

Abstract

In recent studies we described the presence of elastic-type blood vessels within trunci and rami chorii of human placental stem villi. For systemic and pulmonary hypertension it is known that elastic fibres are enhanced in arteries. The aim of our study was, therefore, to examine whether pre-eclampsia may lead to an increase of elastic tissue fibres in blood vessel walls of placental stem villi and whether there are differences in the thickness of blood vessel walls within these villi when compared to normotensive pregnant women. Twenty-six women with uncomplicated pregnancies and 25 patients with pre-eclampsia were investigated. Unfixed cryostat serial sections were processed for conventional orcein staining and for the demonstration of alpha-actin-immunoreactivity. The intensity of orcein staining of stem villus blood vessel walls was evaluated by a semiquantitative score method. Significant higher intensities of orcein staining (P<0.00001) were calculated for blood vessel walls of placentae with pre-eclampsia. The amount of thick stem villus vessels (>41 microm) increased during pre-eclampsia from 39 gestational weeks onwards. Our study demonstrates that segments of thick blood vessel walls and elastic-type vessel walls are increased in placental stem villi of patients with pre-eclampsia. This reaction may protect the fetal placental vessels and avert an increase of the fetal hypertension.

An increase of elastic tissue fibers in blood vessel walls of placental stem villi and differences in the thickness of blood vessel walls in third trimester pre-eclampsia pregnancies

“…When we compared the preeclampsia group with the controls, we found an increase of wall thickness in pre-eclampsia group. Our results were in agreement with the findings of Wilhelm et al [3].…”

“…Wilhelm et al described in their recent study that an increase of elastic tissue fibers in blood vessel walls of placental stem villi during pre-eclampsia when compared to uncomplicated pregnancies, they also described in their another study that elastic tissue fibers were decreased during pregnancies complicated by intrauterin growth retardation, independently of the occurrence of concomitant pre-eclampsia when compared to uncomplicated pregnancies [3]. Similarly, Junek et al indicated that PE induced in umblical cord arteries a decrease of elastin concentration accompanied by a thickening of both the intima and the media.…”

“…Pre-eclampsia is one of the most threatening diseases for mother and child during pregnancy [3]. Barros et al researched the presence of elastic fibers by light and electron microscopy in first, second-trimester and term human placentas.…”

“…Since it is known that elastic tissue fibers increase in systemic hypertension, it may be assumed that the enhancement of elastic tissue fibers in placental stem villi during pre-eclampsia may be induced by the hypertension [10]. Nevertheless, the great range of varieties and the differing amounts of elastic fibers in the blood vessels of all investigated placenta was striking [3].…”

“…Wilhelm et al described the thickness of these blood vessel walls as being enhanced in pre-eclampsia [3]. Umblical arteries, at the fetal side, divide into a number of radially disposed chorionic arteries that branch freely in the chorionic villi.…”