Abstract
Pregnancy in insulin-dependent diabetes mellitus is associated with a greater incidence of fetal abnormality. Animal studies suggested that increased free-radical production and antioxidant depletion may contribute to this risk. The objective of this work was to evaluate oxidative stress and antioxidant capacity in hypertensive, diabetics, and healthy control women during labor. Simultaneous determination of antioxidant enzymes activities, namely glutathione peroxidase (GSH-Px), glutathione reductase (GSH-red), superoxide dismutase (SOD), total antioxidant, and lipid peroxides measured as thiobarbituric acid-reactive substances (TBARS) levels, were carried out in maternal plasma during labor. Plasma GSH-Px activity was found to be significantly increased as it doubled in hypertensive, and diabetic women when compared with healthy control women (P < 0.05). In contrast, plasma SOD activity was significantly decreased in both groups when compared to the control group (P < 0.05). No significant differences were detected in GSH-Red activity between diabetic, hypertensive and control groups. Alterations in antioxidant enzyme activities were accompanied by a significant increase in the levels of plasma lipid peroxides in hypertensive and diabetic women during labor. Plasma levels of total antioxidants were significantly increased in diabetic women as compared with the control group. Based on our results, it may be concluded that enhanced generation of oxidative stress causes alteration of antioxidant capacity in diabetic and hypertensive women during labor. Alterations in antioxidant and prooxidant components may result in various complications including peroxidation of vital body molecules which may be regarded as an increased risk factor for pregnant women as well as the fetus.