Serum and placental lipid peroxides in chronic hypertension during pregnancy with and without superimposed preeclampsia

Objective: To evaluate the circulating levels of lipid peroxides and vitamin E, and the placental levels of lipid peroxides in chronic hypertensive pregnant women, with and without superimposed preeclampsia, as compared to controls and women with primary preeclampsia. Methods: Lipid peroxides were measured in serum and placenta by the thiobarbituric acid method and high-pressure liquid chromatography (HPLC), and vitamin E by HPLC. Patients were 36 healthy pregnant women, 34 previously nonhypertensive women diagnosed with preeclampsia, 20 women with uncomplicated chronic hypertension, and 11 women with chronic hypertension complicated by superimposed preeclampsia. Results: Lipid peroxides in serum and placental tissue were significantly increased, and vitamin E levels in serum were significantly decreased in women with primary preeclampsia and superimposed preeclampsia, as compared to controls. The group of uncomplicated chronic hypertension presented with similar values of lipid peroxides and vitamin E to controls. Conclusions: Our results support the clinical assumption that chronic hypertension aggravated by the development of proteinuria represents a superimposed condition associated with placental disease. The data further support the concept that increased lipid peroxides are not merely associated with the presence of hypertension in pregnancy, but they are implicated in the pathophysiology of preeclampsia.