Avaliação de parâmetros de estresse oxidativo em gestantes gemelares

Abstract

Twin pregnancies are considered to be of high obstetric risk due to several morbidities frequently present due to the increased supply of metabolic compounds to fetuses and the high oxygen consumption by the fetus-placenta unity, leading to the occurrence of oxidative stress and maternal cellular damage. Oxidative stress is present physiologically throughout the gestational period due mainly to the abundant placental activity present due to the high concentration of oxygen, abundant mitochondrial mass, rich vascularization and low endogenous antioxidant capacity, it becomes the main source of reactive oxygen species in the gestation. However, there is little information on twin pregnancies, so this study aimed to evaluate maternal oxidative status in twin pregnant women by determining parameters indicative of oxidative damage in maternal blood in response to the presence of two fetuses, as well as the relationship of the placenta with the increase or not of the oxidative status in these pregnant women and the possible relation with some gestational complications, such as gestational diabetes mellitus and pre-eclampsia. In this way, thiobarbituric acid reactive species (TBARS), proteolytic (P-SH) and non-protein thiol groups (N-PSH), vitamin C (VIT C), as well as catalase (CAT) and enzyme activity delta aminolevulinic dehydratase (δ-ALA-D) as an indirect marker of oxidative stress in blood samples from twin (n = 30) and single fetus (n = 30) pregnant women. As a result, TBARS was significantly higher in twin pregnant women, thiols groupings, VIT C and CAT were significantly lower in these pregnant women than δ-ALA-D activity was reduced in relation to single-fetus pregnant women. The study demonstrated an increase in oxidative stress and a decrease in antioxidant capacity in twin pregnant women, suggesting that the complications present in these pregnancies may be related to the imbalance between levels of oxidants and antioxidants.