Biomarkers of oxidative stress in amniotic fluid and complications in pregnancy

In this study, we tried to determine whether the activities of the primary antioxidant enzymes are detectable in amniotic fluid and whether they can be used as early biomarkers of complications in pregnancy such as pregnancy-induced hypertension (PIH), gestational diabetes mellitus (GDM), and bacterial vaginosis.This was a prospective study in which amniotic fluid was taken between 16 and 19 week of gestation. In all, 161 pregnant women were divided into two groups: study group - patients with the treated local infection, PIH, and GDM, and control group - healthy pregnant women. Levels of reduced glutathione (GSH) and activities of supeoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GSHR), glutathione S-transpherase (GST), xanthine oxidase (XOD) and lipid peroxidation (LP) were determined spectrophotometrically in amniotic fluid samples.Concentration of malondialdehyde varied greatly between investigated groups. XOD and SOD activities, though very low, were present in amniotic fluid samples. Also, enzymes of glutathione cycle and GSH concentrations were detectable and showed certain variations.Parameters of oxidative stress in amniotic fluid could be altered in certain pathological conditions. Their use as clinical biomarkers is limited due to great variations of amniotic fluid volume between patients which gives favor to hemolysate or serum of pregnant women.