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The aim of this study was to evaluate lipid peroxidation and scavenging enzyme activity in streptozotocin-induced diabetes, and then to establish whether moderate doses of nonenzymatic antioxidant vitamin E play a role in the antioxidant defence system in diabetic pregnant rats and their offspring. The study group consisted of 30 normal female Wistar rats, which were given a single dose of streptozotocin (40 mg/kg) and were mated 7 days later. Subsequently, the diabetic animals were divided into two matched groups: the first supplemented with vitamin E (30 mg/100 g chow), and the other fed with a standard diet lacking vitamin E. Controls consisted of 15 pregnant rats. On the first day after delivery, the rats were decapitated and homogenates of maternal liver and uterus as well as neonatal lungs and liver were prepared. Then the following parameters were measured: malondialdehyde (MDA) concentrations in the homogenates and blood serum, glutathione (GSH) levels, the activity of CuZn-superoxide dismutase (SOD) and glutathione peroxidase (GPx), and glycaemia. The neonates of diabetic rats were smaller than the healthy ones and serum glucose concentration was markedly higher in the diabetic animals. MDA levels were significantly increased, whereas GSH, SOD and GPx were markedly diminished in the diabetic adult rats and their offspring in comparison to the control group. In the animals supplemented with alpha-tocopherol, MDA concentrations were significantly lower, GSH content and SOD activities were markedly elevated most tissues studied, whereas GPx remained unchanged. We conclude that, by monitoring the activity of selected scavenging enzymes, information on ongoing biological oxidative stress and thereby on the fetus/neonate status may be obtained. Our results suggest that diabetic pregnant rats and their neonates are exposed to an increased oxidative stress and that vitamin E supplementation may reduce its detrimental effects.

Gestational Diabetes Mellitus (GDM) causes severe short- and long-term complications for the mother, fetus and neonate, including type 2-diabetes (T2DM) later in life. In this pilot study, GC-Q/MS analysis was applied for plasma metabolomics fingerprinting of 24 healthy and 24 women with GDM at different stages of gestation (second and third trimester) and postpartum (one and three months). Multivariate (unsupervised and supervised) statistical analysis was performed to investigate variance in the data, identify outliers and for unbiased assessment of data quality. Plasma fingerprints allowed for the discrimination of GDM pregnant women from controls both in the 2nd and 3rd trimesters of gestation. However, metabolic profiles tended to be similar after delivery. Follow up of these women revealed that 4 of them developed T2DM within 2 years postpartum. Multivariate PLS-DA models limited to women with GDM showed clear separation 3 months postpartum. In the 2nd trimester of gestation there was also a clear separation between GDM women that were normoglycemic after pregnancy and those with recognized postpartum T2DM. Metabolites that had the strongest discriminative power between these groups in the 2nd trimester of gestation were 2-hydroxybutyrate, 3-hydroxybutyrate, and stearic acid. We have described, that early GDM comprises metabotypes that are associated with the risk of future complications, including postpartum T2DM. In this pilot study, we provide evidence that 2-hydroxybutyrate and 3-hydroxybutyrate may be considered as future prognostic biomarkers to predict the onset of diabetic complications in women with gestational diabetes after delivery.

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Pregnancy complicated by poor control of diabetes is associated with a higher risk of embryopathies, spontaneous abortions and perinatal mortality. A number of authors suggest an involvement of reactive oxygen species (ROS) in diabetic pregnancy. Determining lipid peroxidation products (LP), scavenging enzyme activities and the umbilical cord blood's acid-base balance may contribute to an adequate diagnosis of the neonate at birth. Nevertheless, such measurements seem to have limited value in practical clinical routine. The present study evaluates LP, antioxidant defence and acid-base status related to diabetic pregnancy. Twenty-eight women with type 1 diabetes (PGDM), 19 with gestational diabetes (GDM) and 13 control cases were investigated. An additional control group consisted of 15 healthy patients with negative diabetic history; all women underwent vaginal delivery. Immediately after delivery cord blood samples and placental tissue were collected for malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) determination. Additionally, pH, pCO2, pO2 and base excess were measured in both vessels and compared to identify and exclude double venous samples. MDA levels in both cord blood and placental homogenates were significantly higher in both pregestational and gestational diabetic groups, but SOD activity was significantly diminished. Cord blood GSH was markedly elevated in PGDM and GDM. We have also shown significant differences in acid-base parameters in infants of PGDM group. Statistical analysis was performed using the Mann-Whitney U-test. These findings indicate an excessive oxidative stress in pregnancy complicated by diabetes mellitus. Evaluating LP products and scavenging enzyme activities may be valuable, sensitive indexes of fetal/neonatal threat in diabetic pregnancy in humans. Since oxidative stress is an important pathway for fetal injury, we believe that obtaining adequate measurements at the time of birth would contribute to clarifying the fetal/neonatal status in a medical and legal context and might be of value in altering therapy in newborn infants.