Investigation of free radical scavenging enzyme activities and lipid peroxidation in human placental tissues with miscarriage.

Background: Miscarriage (early pregnancy failure) is a pregnancy-related disease, the pathophysiology of which is still not completely understood. Lipid peroxidation and alterations in antioxidant enzyme activities may be of importance in the pathogenesis of this disorder. This study was planned to investigate the possible relation between free radical scavenging enzyme activities and lipid peroxidation levels in placenta tissues with miscarriage.

Methods: Placental tissue samples were obtained from 21 patients who had miscarried and 25 normal pregnant women undergoing elective abortion as a control group. Total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) enzyme activities and levels of thiobarbituric acid reactive substances (TBARS), antioxidant potential (AOP), and nonenzymatic superoxide radical scavenger activity (NSSA) were measured in the placental tissues.

Results: GSH-Px, CAT activities, and TBARS levels were found to be significantly increased, while T-SOD and NSSA values decreased in patients with early pregnancy failure when compared with women undergoing elective abortion (control group). However, there were no significant differences in AOP levels between the groups.

Conclusions: Our results reflect oxidative stress in placenta tissues of early pregnancy failure, as the oxidative processes seem to be counteracted by the physiologic activation of antioxidant enzymes such as CAT and GSH-Px. Moreover, a compensatory mechanism might be developed against possible oxidative damage in patients with miscarriage.