Evaluation of oxidative stress and δ-aminolevulinate dehydratase activity in twin pregnancies.

To assess and understand the maternal oxidative stress in twin pregnancies, currently not studied, through ascertain indicators of oxidative damage in maternal blood in response of two fetuses, as well as the relation of placenta with or without the increase of oxidative stress in these gestations. The activity of delta-aminolevulinate dehydratase (δ-ALA-D) was analyzed as an indirect marker of oxidative stress, as well as the quantification of thiobarbituric acid reactive substances (TBARS), protein thiol groups (P-SH) and nonprotein thiol groups (NP-SH), vitamin C (VIT C) and catalase activity (CAT) in maternal blood samples from twin ( = 30) and single ( = 30) pregnancies. This study was approved by the Human Ethics Committee UFSM (register by the number 49823015.4.0000.5346). TBARS was significantly higher in twin pregnancies, while thiol groups, VIT C and CAT were decreased, asides from the reduced activity of δ-ALA-D in comparison to single fetus gestations. The study established an oxidative stress increased and an antioxidant ability decreased in twin pregnancies, suggesting a possible relation between the levels of oxidants and antioxidants with the complications in those gestations.