Oxidative Stress In Pregnancy Research Articles

Apelin levels in normal pregnancy

Apelin is an adipokine secreted from adipose and other tissues with increased expression in obesity, role in glucose metabolism and atherosclerosis, as well as in oxidative stress. Pregnancy is considered a state of hyperlipidemia, oxidative stress and decreased insulin sensitivity. The aim of the present study is to investigate the levels of apelin in human pregnancy and its relation to insulin sensitivity. One hundred and six pregnant women (24th-28th week of gestation), aged 27·9 ± 0·4 years, were compared to 106 age-matched healthy, nonpregnant women (controls). Measured parameters included serum levels of glucose, insulin, apelin, adiponectin, total cholesterol, high-density lipoprotein (HDL) and low-density lipoprotein (LDL), triglycerides and oxidized LDL (ox-LDL). The body mass index (BMI) and the quantitative insulin sensitivity check index (QUICKI) were calculated as well. BMI, serum lipids and insulin levels were significantly higher, whereas serum apelin and glucose levels were lower in the pregnancy group compared to the control group. There was a significant negative correlation between apelin and adiponectin, in both groups. Additionally, apelin was negatively correlated with ox-LDL and HDL-cholesterol in the pregnancy group. Although strongly correlated with adiponectin, apelin cannot be used as a marker of insulin sensitivity, but it could serve as a marker of oxidative stress in pregnancy.

Thiobarbituric acid reactive substances as marker of oxidative stress in pregnancies with pre-eclampsia

Pre-eclampsia is characterized by increased lipid peroxidation and diminished antioxidant capacity. The aim of the study was to establish concentration of thiobarbituric acid reactive substances as a marker of lipid peroxidation in normal pregnancies and in pregnancies complicated with pre-eclampsia, and to estimate the possibility of using thiobarbituric acid reactive substances as a screening method for development of pre-eclampsia. The study was conducted at the Department of Obstetrics and Gynaecology, Clinical Centre of Vojvodina. The study included 57 singleton pregnancies, gestation > or = 24 weeks, of which 29 were healthy pregnancies and 28 were with pre-eclampsia, defined as systolic arterial pressure of > or = 90 mmHg, diastolic of > or = 145 mmHg, and 24h proteinuria of > or = 300 mg. Thiobarbituric acid reactive substances concentrations evaluated by malondialdehyde equivalent standards (OxiSelect TBARS Assay Kit (malondialdehyde Quantitation), Cell Biolabs' OxiSelect) showed that oxidative stress was more evident in the group with pre-eclampsia, though not statistically significant (p = 0.107). There was no correlation ofthiobarbituric acid reactive substance levels with gestation in either group. The differences between the level of thiobarbituric acid reactive substance concentrations in pre-eclampsia and healthy pregnancies indicate the possibility of using thiobarbituric acid reactive substances as a screening tool for the development of pre-eclampsia. Further studies with larger numbers of patients are needed in order to come to final conclusions.

Maternal lipid metabolism during normal pregnancy and its implications to fetal development

Whereas accumulation of fat depots occurs during the first two-thirds of gestation, increased adipose tissue lipolysis and hyperlipidemia develops in the last trimester. Insulin resistance and increased estrogens in late pregnancy contribute to these changes. Lipoprotein receptors and fatty acid binding proteins in the placenta allow the transfer of long-chain polyunsaturated fatty acids to the fetus. Enhanced oxidative stress in pregnancy may be related to maternal hyperlipidemia. Maternal plasma nonesterified fatty acids and cholesterol correlate with those in the fetus, and maternal adipocytokines have been associated with fetal growth. However, positive correlations between maternal nonesterified fatty acids or triacylglycerols and neonatal body weight or fat mass have only been found in gestational diabetics. Under the limited capacity of the fetus to modify the structure of essential polyunsaturated fatty acids, their long-chain derivatives have to be transferred from the mother through the placenta in appropriate amounts to warrant the normal fetal development.

Association between oxidative stress in pregnancy and preterm premature rupture of membranes

Background: Premature rupture of membranes (PROM) is caused by collagen damage in the chorioamniotic sac leading to tearing. Reactive oxygen species (ROS) may be the cause of collagen damage. Isoprostanes (F 2-IP) are produced by ROS attack on polyunsaturated fatty acids and are sensitive and specific biomarkers of lipid-peroxidation in vivo. Aim: To verify whether oxidative stress occurs in pregnancies associated with preterm PROM. Methods: F 2-IPs were measured in amniotic fluid of 16 pregnancies with preterm PROM (Group II) and 97 without PROM (Group I). Results: F 2-IP concentrations (pg/mL) were significantly higher in group II than group I ( p < 0.0001). The ROC curve showed a sensitivity of 100% and a specificity of 84.5% at a cut-off of 124.4 pg/mL. Conclusions: An association exists between oxidative stress in pregnancy and preterm PROM. The detection of amniotic fluid F 2-IP concentrations seems to be a reliable predictive index of risk of preterm PROM.

Indices of oxidative stress in pregnancy with fetal growth restriction

Intrauterine fetal growth restriction (IUGR), the main cause of premature delivery and fetal mortality, has been suggested to involve oxidative stress. We found elevated values of indices of oxidative stress in the blood serum of pregnant women with IUGR: increased levels of malondialdehyde and 4-hydroxyalkenals, decreased activity of α-1-antitrypsin and decreased total antioxidant capacity of the serum, with respect to healthy pregnancy. Twenty day treatment with 3 g of l-arginine and 75 mg of acetylsalicylic acid daily resulted in a decrease of the level of lipid peroxidation products and augmentation of α-1-antitrypsin activity. This study confirms the occurrence of oxidative stress in IUGR and demonstrates the beneficial effect of arginine/acetylsalicylic acid therapy in reducing oxidative stress in IUGR.

Iron prophylaxis in pregnancy—general or individual and in which dose?

Iron is mandatory for normal fetal development, including the brain. Iron deficiency may have deleterious effects for intelligence and behavioral development. It is important to prevent iron deficiency in the fetus by preventing iron deficiency in the pregnant woman. Iron deficiency anemia during pregnancy is a risk factor for preterm delivery and low birth weight. In the Western countries there is no consensus on iron prophylaxis to pregnant women. An adequate iron balance during pregnancy implies body iron reserves of >or=500 mg at conception. The physiologic iron requirements in the second half of gestation cannot be fulfilled solely through dietary iron. Iron supplements during gestation consistently increase serum ferritin and hemoglobin and reduce the prevalence of iron deficiency anemia. Iron has a negative influence on absorption of other divalent metals and increases oxidative stress in pregnancy, for which reason minimum effective iron dose should be advised. From a physiologic point of view, individual iron prophylaxis according to serum ferritin concentration should be preferred to general prophylaxis. Suggested guidelines are (1) ferritin>70 microg/l: no iron supplements; (2) ferritin 30-70 microg/l: 40 mg ferrous iron daily; and (3) ferritin<30 microg/l: 80-100 mg ferrous iron daily. In controlled studies, there are no documented side effects of iron supplements below 100 mg/day. Iron supplements should be taken at bedtime or between meals to ensure optimum absorption.

Evaluation of oxidative stress in pregnancy induced hypertension

This work was undertaken to investigate correlation between oxidative stress and initiation of pathogenesis of pregnancy induced hypertension (PIH). Fifty primigravidae in age group of 20-35 years and gestational age 28-42 weeks with PIH were taken as cases. Twenty healthy primigravidae with no medical and surgical complications of pregnancy and with blood pressure ≤140/90 mm Hg served as controls. The cases were again subgrouped as severe preeclampsia (12 in number) and mild pre-eclampsia (38 in number). All of them were evaluated for serum malondialdehyde (MDA), Serum vitamin E and plasma vitamin C levels. The serum MDA levels were raised significantly in women with mild preeclampsia (P<0.01) and in women with severe preeclampsia (P<0.01) in comparison to normal primi gravida. The serum vitamin E levels were decreased in primi gravida with mild preeclampsia (p<0.1) and in primi with severe pre eclampsia (P<0.1) in comparison to normal primi gravida but the fall was not statistically significant. There was a significant fall (P<0.05) in the vitamin C levels in primi with mild preeclampsia than in the normal primi. The vitamin C levels in severe preeclamptic patients were lower than the normal primi but the fall was not statistically significant (P=0.10). The serum MDA and vitamin E showed a negative correlation in all the cases. The serum MDA and plasma vitamin C also showed a negative correlation in the control and study group. This observation suggests that in hypertensive disorders of pregnancy there is an imbalance between lipid peroxidation and antioxidant vitamin status because of oxidative stress. The decreased serum concentrations of the antioxidant vitamins supports the hypothesis that lipid peroxidation is an important causative factor in the pathogenesis of preeclampsia. The rise in antioxidants is probably to compensate the increased peroxide load in severe preeclampsia.

Some Biochemical Markers of Oxidative Stress in Pregnant Nigerian Women

Context: The increased generation of free radicals and reactive oxygen species in pregnancy results in oxidative stress. Antioxidants are used as defence mechanisms and their serum concentrations give oxidative stress levels. Objective: To determine serum levels of ascorbic acid, uric acid and bilirubin (antioxidants) , as simple markers of oxidative stress in pregnant Nigerian women. Study Design, Setting, Subjects and Methods: Pregnant women numbering sixty-five, aged between 20-38 years, in their second and third trimesters were selected from the antenatal clinic, University of Nigeria Teaching Hospital (UNTH) Enugu. A comparable group of 65 non-pregnant women (controls) were also recruited. Serum levels of ascorbic acid were determined by Roe and Kenther method, uric acid by Brown\'s method and bilirubin by Powell\'s method. Results: The serum levels of ascorbic acid, uric acid and bilirubin were each significantly lower in pregnant than in non-pregnant control subjects (p Conclusion : Antioxidant estimation may be useful in the assessment of the degree of oxidative stress in pregnancy. Increased intake is thus advocated. Key Words: Antioxidants, biochemical markers, oxidative stress, pregnancy. [Trop J Obstet Gynaecol, 2004; 21:122-124]

Meconium-stained liquor during labor is associated with raised neonatal cord blood 8-iso-prostaglandin F2α concentration

The purpose of this study was to compare the umbilical arterial 8-iso-prostaglandin F2alpha, concentrations between pregnancies that were complicated by moderate or thick meconium-stained liquor and those with clear liquor. Umbilical cord arterial blood samples were collected from 247 singleton pregnancies with either moderate or thick meconium-stained liquor at any stage of labor or clear liquor at all stages of labor for the determination of the total 8-iso-prostaglandins F2alpha concentration. The median total 8-iso-prostaglandins F2alpha concentration of the meconium-stained liquor group was significantly higher than that of the control group (719.2 vs 115.8 pg/mL). Among the meconium-stained liquor group, those who had a change from "clear liquor" at early labor to "moderate/ thick meconium-stained liquor" at late first stage or at delivery (late meconium-stained liquor group) had higher 8-iso-prostaglandins F2alpha concentration, compared with those who had moderate/ thick meconium-stained liquor since early labor (early meconium-stained liquor group; 959.8 vs 499.9 pg/mL). With the use of multiple regression analysis, meconium-stained liquor, duration of second stage of labor, and abnormal fetal heart tracings were independent determinants of cord blood 8-iso-prostaglandins F2alpha concentration. Moderate or thick meconium-stained liquor is an independent factor for increased oxidative stress in pregnancy.

Iron and Oxidative Stress in Pregnancy

Pregnancy, mostly because of the mitochondria-rich placenta, is a condition that favors oxidative stress. Transitional metals, especially iron, which is particularly abundant in the placenta, are important in the production of free radicals. Protective mechanisms against free radical generation and damage increase throughout pregnancy and protect the fetus, which, however, is subjected to a degree of oxidative stress. Oxidative stress peaks by the second trimester of pregnancy, ending what appears to be a vulnerable period for fetal health and gestational progress. Conditions restricted to pregnancy, such as gestational hypertension, insulin resistance and diabetes, exhibit exaggerated indications of free radical damage. Antioxidants as well as avoidance of iron excess ameliorate maternal and early fetal damage. In rats both iron deficiency and excess result in free radical mitochondrial damage. Estimates of gestational iron requirements and of the proportion of iron absorbed from different iron supplemental doses suggest that with present supplementation schemes the intestinal mucosal cells are constantly exposed to unabsorbed iron excess and oxidative stress. Unpublished work carried out in Mexico City with nonanemic women at midpregnancy indicates that 60 mg/d of iron increases the risk of hemoconcentration, low birth weight and premature birth and produces a progressive decline in plasma copper. These risks are not observed in women supplemented with 120 mg iron once or twice per week. Studies on the influence of iron supplementation schemes on oxidative stress are needed.

Lipid peroxidation, antioxidant defence and acid-base status in cord blood at birth: the influence of diabetes.

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.

Oxidative stress in pregnancy induced hypertensive disorders

Oxidative stress in pregnancy induced hypertensive disorders

Fetal plasma lipid peroxide levels in pregnancies complicated by preeclampsia.

Fetal levels of a representative lipid peroxide malondialdehyde (MDA) were measured as an index of oxidative stress in pregnancies complicated by preeclampsia (n = 19) and in normal pregnancy (n = 23). PO2, PCO2 and pH were also measured in umbilical venous blood obtained by cordocentesis. Plasma MDA levels rose an average of 26% above those of normal pregnancy (p < 0.05) and the elevation correlated inversely with umbilical venous PO2 and pH. The results indicate that fetal oxidative stress occurs in preeclampsia before the onset of labor.