Preeclampsia (PE) is a pregnancy-specific disorder, defined as new onset of maternal hypertension and proteinuria after 20 weeks of gestation. Our earlier study has shown increased maternal oxidative stress at delivery to be associated with poor birth outcome in PE. However, these results were observed when the pathology had progressed and may have been secondary to the effects of the disorder. To understand the role of antioxidant defense mechanisms in PE right from early pregnancy, in this prospective study, we measured malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione (GSH) concentrations in maternal blood at 3 time-points of gestation [16-20 weeks (T1), 26-30 weeks (T2), at delivery (T3)] and in cord blood. Gene expression of SOD and GPx and protein levels of endothelial nitric oxide synthase (eNOS) enzyme were also analyzed in the placenta. MDA levels were higher at T1 (p < 0.01) and T2 (p < 0.01) in women with PE as compared with control. GPx levels were higher at T3 (p < 0.05) while SOD levels were lower at T2 (p < 0.05), T3 (p < 0.01) and in cord (p < 0.01) in PE. GSH levels at T1 (p < 0.05) and expression of GPx in the placenta were lower in PE as compared with control. In conclusion, this study demonstrates that women who develop PE exhibit increased oxidative stress right from 16 to 20 weeks of gestation. This may alter placental development and lead to fetal programming of adult non-communicable disease in the offspring.
Keywords: Antioxidants; early pregnancy; longitudinal study; oxidative stress; placenta; preeclampsia.