OBJECTIVETo investigate whether pregnancy-induced hypertension (PIH) may increase oxidative stress in women with PIH, and to explore the mechanisms by which PIH may increase oxidative stress and potential free radical damage.

METHODSSeventy women with PIH and seventy women with uncomplicated normotensive pregnancy (UNP) whose age, nutritional conditions, levels of hemoglobin and albumin were all matched, were enrolled in a randomized controlled trial. Their plasma concentrations of nitric oxide (NO), vitamin C (VC), vitamin E (VE), and beta-carotene (beta-CAR) as well as their erythrocyte malondialdehyde (MDA), and activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) were determined by spectrophotometry.

RESULTSCompared with average values of the above experimental parameters in the women with UNP, the average value of erythrocyte MDA in the women with PIH significantly increased (P<0.0001), while the average values of plasma NO, VC, VE, and beta-CAR as well as those of erythrocyte SOD, CAT, and GPX in the women with PIH significantly decreased (P<0.0005-0.0001). The findings from partial correlation analysis (controlling for age) for 70 women with PIH showed that with elevated systolic blood pressure (SBP) and diastolic blood pressure (DBP), MDA value gradually increased (P<0.001), and NO, VC, VE, beta-CAR, SOD, CAT, and GPX values gradually decreased (P<0.02-0.001). The findings from reliability analysis for NO, VC, VE, beta-CAR, SOD, CAT, GPX, and MDA values used to reflect increased oxidative stress and potential free radical damage in women with PIH showed that the reliability coefficients (alpha, 8 items) = 0.7062, P<0.0001, and the standardized item alpha = 0.9116, P<0.0001.

CONCLUSIONThe findings in the present research suggest that pregnancy-induced hypertension can increase oxidative stress and potential free radical damage in women with pregnancy-induced hypertension.