Oxidant-antioxidant system changes relative to placental-umbilical pathology in patients with preeclampsia

It is speculated that lipid peroxidation is responsible for the pathologic changes that occur in the uteroplacental vasculature of women with preeclampsia. The aim was to investigate this proposed relationship.

The prospective study involved 90 pregnant women. Thirty had mild preeclampsia, 30 had severe preeclampsia, and 30 were healthy pregnant women (controls). The data collected for each case were umbilical cord and placental pathologies, plasma malondialdehyde (MDA) level, and levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity in erythrocytes. Group findings were compared.

The mean MDA level in the severe preeclampsia group was higher than the corresponding findings in the mild preeclampsia and control groups (p < 0.001 for both). Also, the MDA level in the mild preeclampsia group was significantly higher than was the control level (p < 0.001). The mean SOD activity level in the severe preeclampsia group was lower than the corresponding results in the mild preeclampsia and control groups (p < 0.001 for both). The mean GSH-Px levels in the mild and severe preeclampsia groups were both significantly lower than was the corresponding finding in the control group (p < 0.01). Compared to the control group, both preeclampsia groups had significantly higher frequencies for placental infarction, villous fibrosis, increased numbers of syncytial nodes, and thickening of vessel walls and lumen obliteration (p < 0.001 for all). Villous fibrinoid necrosis, perivillous fibrosis, and increased villous vascularization were also significantly more frequent in both preeclampsia groups than in the control group, but the differences for these parameters were smaller (p < 0.01 for all). Examination of the samples from the placental ends of the umbilical cords revealed significantly higher frequencies of endothelial irregularity, endothelial shedding, and basal membrane thickening in both preeclampsia groups than in those of the control group (p < 0.001). The same findings were noted in the middle sections of the cords (p < 0.001). At the fetal ends of the umbilical cords, both preeclampsia groups had higher frequencies of endothelial irregularity than did the control group (p < 0.001); however, the frequencies of the more severe pathologic findings (endothelial shedding, basal membrane thickening) in the three groups were similar.

The frequencies of pathologic changes in the placenta and umbilical vessels of women with preeclampsia parallel the severity of this condition. These changes also parallel plasma levels of MDA, the end product of lipid peroxidation.