Abstract: Objective To detect systematic oxidative stress in preeclampsia. Methods ① Morphological features of placenta hypoxia were observed by histological method;② Levels of granulocyte intracellular reactive oxygen species monitored by dyeing full blood with 2',7'-dichlorodihydrofluorescein diacetate(H2DCFDA); ③ Levels of H2O2 in sera were detected by special kits. Results Compared to normal pregnancy, placentas from preeclampsia showed distinct features of hypoxic stress injury, such as more syncytial knots formation, fibrosis emerged, vein injury and loss its normal configuration; Fluorescence values of ROS probe in neutrophils from different women were 45.61±12.2 ?mol/L（n=49）, 51.02±13.6 ?mol/L（n=56, p<0.01）and 85.1±16.3?mol/L（n=47, p<0.01）; Concentrations of H2O2 were 24.57±5.17 ?mol/L（n=49）, 26.61±3.25 ?mol/L（n=56, p>0.01） and 39.84±9.67（n=47, p<0.01） respectively. Conclusions With the help of histological method, flow cytometry and special kits, levels of systematic oxidative stress can be detected in placentic tissues, netrophils and sera of preeclampsia.

Key words: preeclampsia, oxidative stress, placenta, PMN