OBJECTIVE: The purpose of study was to assess in a longitudinal study of maternal plasma concentrations of Tumor necrosis factor-alpha(TNF-alpha), Vascular cell adhesion molecule-1(VCAM-1), Lipid peroxide (malonaldehyde, MDA) in uncomplicated pregnancy. METHODS: Blood was collected from healthy women at 4 to 41 weeks' gestation and non-pregnant women. Plasma samples were measured by immunoassay for TNF-alpha, VACM-1 and by colorimetric assay for lipid peroxide, and data were statistically analyzed. RESULTS: Plasma concentration of TNF-alpha was not significantly elevated during first trimester compared with non-pregnant women, but significantly elevated during second and third trimester compared with non-pregnant women. Plasma concentration of VCAM-1 was significantly elevated during first trimester compared with non-pregnant women. Plasma concentration of lipid peroxide was not significantly elevated during pregnancy compared with non-pregnant women. CONCLUSION: The plasma concentration of TNF-alpha and VCAM-1 were significantly higher than that of non-pregnant state during second and third trimester in case of TNF-alpha, and during first trimester in case of VCAM-1. But the plasma concentration of lipid peroxide during pregnancy was not significantly different from that of non-pregnant, and the plasma concentration was kept up constant levels during gestation. These were seems to be meant that abnormal pregnancy would be happened if the level is above or below the measured level.