ascorbic-acid and Hypertension--Pregnancy-Induced

To perform a systematic review and meta-analysis of the effectiveness of combined vitamin C and E (vitCE) supplementation for the prevention of preeclampsia.. PubMED, Web of Science, and Cochrane Central Register of Controlled Trials from inception through June 2010, and bibliographies of review articles and eligible studies.. Fifteen eligible studies that evaluated vitCE supplementation for the prevention of preeclampsia were identified. On the basis of prespecified inclusion and exclusion criteria, 9 were included in the meta-analysis. All were randomized controlled trials. The reporting and methodologic quality of the included studies was assessed with the CONSORT checklist and the Jadad scale.. The 9 included studies had moderate-to-high CONSORT and Jadad scores. The incidence of preeclampsia was 9.7% (949 of 9833) in the vitCE group and 9.5% (946 of 9842) in the placebo group. A random effects model was used for pooling and no difference was found in the relative risk (RR) of preeclampsia between the vitCE and placebo groups (RR: 0.98; 95% confidence interval [CI]: 0.87-1.10). The incidence of gestational hypertension was 22.6% (1915 of 8491) in the vitCE group and 20.3% (1728 of 8500) in the placebo group (RR: 1.11, 95% CI: 1.05-1.17). The incidence of placental abruption was 0.58% (43 of 7379) in the vitCE group and 0.87% (64 of 7361) in the placebo group (RR: 0.67, 95% CI: 0.46-0.98). No significant differences were observed for other maternal and neonatal outcomes.. Combined VitCE supplementation does not decrease the risk of preeclampsia and should not be offered to gravidas for the prevention of preeclampsia or other pregnancy induced hypertensive disorders. Furthermore, combined supplementation with vitCE increased the risk of GH but decreased the risk of placental abruption. However, these latter associations may not be causal, especially since they were the product of multiple statistical comparisons, and the 95% CI around the point estimates almost included one.. After completion of this educational activity, the obstetrician/gynecologist should be better able to assess the causes of preeclampsia and related conditions; evaluate and interpret the evidence regarding the use of combined vitamins C and E in prevention of preeclampsia and related conditions; and interpret and understand the effects of the supplementation of vitamins C and E for the prevention of preeclampsia or other pregnancy induced hypertensive disorders.. Obstetricians & Gynecologists, Family Physicians.

Topics: Ascorbic Acid; Dietary Supplements; Drug Therapy, Combination; Female; Humans; Hypertension, Pregnancy-Induced; Pre-Eclampsia; Pregnancy; Vitamin E

Smoking and pre-eclampsia (PE) are associated with increases in preterm birth, placental abruption and low birthweight. We evaluated the relationship between prenatal vitamin C and E (C/E) supplementation and perinatal outcomes by maternal self-reported smoking status focusing on outcomes known to be impacted by maternal smoking.. A secondary analysis of a multi-centre trial of vitamin C/E supplementation starting at 9-16 weeks in low-risk nulliparous women with singleton gestations.. We examined the effect of vitamin C/E by smoking status at randomisation using the Breslow-Day test for interaction.. The trial's primary outcomes were PE and a composite outcome of pregnancy-associated hypertension (PAH) with serious adverse outcomes. Perinatal outcomes included preterm birth and abruption.. There were no differences in baseline characteristics within subgroups (smokers versus nonsmokers) by vitamin supplementation status. The effect of prenatal vitamin C/E on the risk of PE (P = 0.66) or PAH composite outcome (P = 0.86) did not differ by smoking status. Vitamin C/E was protective for placental abruption in smokers (relative risk [RR] 0.09; 95% CI 0.00-0.87], but not in nonsmokers (RR 0.92; 95% CI 0.52-1.62) (P = 0.01), and for preterm birth in smokers (RR 0.76; 95% CI 0.58-0.99) but not in nonsmokers (RR 1.03; 95% CI 0.90-1.17) (P = 0.046).. In this cohort of women, smoking was not associated with a reduction in PE or the composite outcome of PAH. Vitamin C/E supplementation appears to be associated with a reduction in placental abruption and preterm birth among smokers.

Topics: Abruptio Placentae; Adolescent; Adult; Ascorbic Acid; Dietary Supplements; Double-Blind Method; Female; Humans; Hypertension, Pregnancy-Induced; Pre-Eclampsia; Pregnancy; Premature Birth; Smoking; Vitamin E; Vitamins; Young Adult

Hypertension occurs in 6 to 10 percent of pregnancies. It remains one of the most common disorders in pregnancy and the leading causes of maternal and fetal morbidity The changes in blood vessel endothelium have impact on the pathogenesis of hypertension and preeclampsia.. The aim of this study was to establish endothelin- 1 and lipids peroxides content in blood during hypertension and the influence of vitamin C and E supplementation on the concentration of both parameters.. Two study groups (pregnancy complicated with hypertension, pregnancy complicated with hypertension treated with vitamins C and E) and a control group with uncomplicated pregnancies were distinguished. Blood samples from maternal peripheral venous circulation were collected and ET-1 and lipids peroxides levels were determined from the blood samples.. Concentration of endothelin-1 in the group with hypertension and with vitamin supplementation was INCREASED (66.18 +/- 26.66 pg/ml) in comparison with normal pregnant (36.50 +/- 13.25) and hypertension group (41.02 +/- 15.98). The difference was significant. Lipid peroxides concentrations were significantly higher in the group with hypertension (1.18 +/- 0.69) in comparison with both groups - controls (0.73 +/- 0.35) and the group with hypertension and vitamin supplementation (0.77 +/- 0.42).. No significant differences in the endothelin- 1 level between healthy pregnant and pregnant women with hypertension were found. Vitamin supplementation decreases the concentrations of lipid peroxides.

Topics: Administration, Oral; Ascorbic Acid; Biomarkers; Drug Administration Schedule; Endothelin-1; Female; Humans; Hypertension; Hypertension, Pregnancy-Induced; Lipid Peroxides; Pregnancy; Vitamin E

We sought to investigate whether prenatal vitamin C and E supplementation reduces the incidence of gestational hypertension (GH) and its adverse conditions among high- and low-risk women.. In a multicenter randomized controlled trial, women were stratified by the risk status and assigned to daily treatment (1 g vitamin C and 400 IU vitamin E) or placebo. The primary outcome was GH and its adverse conditions.. Of the 2647 women randomized, 2363 were included in the analysis. There was no difference in the risk of GH and its adverse conditions between groups (relative risk, 0.99; 95% confidence interval, 0.78-1.26). However, vitamins C and E increased the risk of fetal loss or perinatal death (nonprespecified) as well as preterm prelabor rupture of membranes.. Vitamin C and E supplementation did not reduce the rate of preeclampsia or GH, but increased the risk of fetal loss or perinatal death and preterm prelabor rupture of membranes.

Topics: Adult; Antioxidants; Ascorbic Acid; Dietary Supplements; Double-Blind Method; Female; Fetal Death; Fetal Membranes, Premature Rupture; Humans; Hypertension, Pregnancy-Induced; Pre-Eclampsia; Pregnancy; Prenatal Care; Risk; Risk Factors; Vitamin E

Oxidative stress has been proposed as a mechanism linking the poor placental perfusion characteristic of preeclampsia with the clinical manifestations of the disorder. We assessed the effects of antioxidant supplementation with vitamins C and E, initiated early in pregnancy, on the risk of serious adverse maternal, fetal, and neonatal outcomes related to pregnancy-associated hypertension.. We conducted a multicenter, randomized, double-blind trial involving nulliparous women who were at low risk for preeclampsia. Women were randomly assigned to begin daily supplementation with 1000 mg of vitamin C and 400 IU of vitamin E or matching placebo between the 9th and 16th weeks of pregnancy. The primary outcome was severe pregnancy-associated hypertension alone or severe or mild hypertension with elevated liver-enzyme levels, thrombocytopenia, elevated serum creatinine levels, eclamptic seizure, medically indicated preterm birth, fetal-growth restriction, or perinatal death.. A total of 10,154 women underwent randomization. The two groups were similar with respect to baseline characteristics and adherence to the study drug. Outcome data were available for 9969 women. There was no significant difference between the vitamin and placebo groups in the rates of the primary outcome (6.1% and 5.7%, respectively; relative risk in the vitamin group, 1.07; 95% confidence interval [CI], 0.91 to 1.25) or in the rates of preeclampsia (7.2% and 6.7%, respectively; relative risk, 1.07; 95% CI, 0.93 to 1.24). Rates of adverse perinatal outcomes did not differ significantly between the groups.. Vitamin C and E supplementation initiated in the 9th to 16th week of pregnancy in an unselected cohort of low-risk, nulliparous women did not reduce the rate of adverse maternal or perinatal outcomes related to pregnancy-associated hypertension (ClinicalTrials.gov number, NCT00135707).

Topics: Adult; Antioxidants; Ascorbic Acid; Double-Blind Method; Drug Combinations; Female; Humans; Hypertension, Pregnancy-Induced; Oxidative Stress; Parity; Pre-Eclampsia; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Pregnancy Trimester, First; Treatment Failure; Vitamin E; Young Adult

A case-control study of 10,228 gestational women was conducted in Lanzhou, China, between 2010 and 2012. This study aimed to evaluate the associations between the risk of gestational hypertensive disorders and dietary intake of vitamin C/E. Among this study's participants, 5.41% (n=553) were diagnosed with gestational hypertensive disorders. Of these disorders, 69.44% (n=384) were preeclampsia and 30.56% (n=169) were considered to be gestational hypertension. After adjustment for confounding variables and other relevant dietary nutrients, no association was found between the risk of gestational hypertensive disorders and dietary intake of vitamin C, vitamin E, copper or manganese before or during pregnancy. However, zinc and selenium intake was associated with the decrease risk of gestational hypertensive disease during different stages of pregnancy (p<0.05). Gestational dietary intake of zinc and selenium can significantly decrease the risk of gestational hypertensive disorders. No association was found between gestational hypertensive disorders and vitamin C, vitamin E, copper or manganese intake.

Topics: Adult; Ascorbic Acid; Case-Control Studies; Diet; Female; Humans; Hypertension, Pregnancy-Induced; Pregnancy; Risk Factors; Selenium; Vitamin E; Young Adult; Zinc

To explore the relationship, if any, between dietary intake of the antioxidant vitamins C and E, and the development of pre-eclampsia and gestational hypertension.. A prospective cohort study of pregnant women attending the antenatal clinic of the Women's and Children's Hospital in Adelaide, Australia, was carried out between April and July 2001. Women completed a semi-quantitative 116-item food frequency questionnaire (FFQ). Women's medical records were viewed after birth to collect data on pregnancy outcomes. Relationships were explored through cross-tabulations, chi-square analysis, and adjustments were made for potential confounders using binary logistic regression.. A total of 299 women completed the FFQ. Median intake of vitamin C was 188 mg and for vitamin E was 6.74 mg. There was no relationship between the intake of vitamin C and hypertensive disorders of pregnancy. For vitamin E, being in the lowest quartile of intake, was associated with an increased risk of hypertensive disorders (RR 1.75, 95% CI 1.11-2.75, P = 0.02). This relationship was confirmed after adjusting for the confounding factors of maternal age and parity.. Little support was found for a relationship between dietary intake of vitamin C and the development of hypertensive disorders of pregnancy. Low vitamin E intake was associated with a significant increase in the risk of hypertensive disorders of pregnancy, even after adjustments were made for confounding factors. Further research is required to investigate whether supplementation above dietary intake of antioxidant vitamins influences the risk of hypertensive disorders of pregnancy.

Topics: Adult; Antioxidants; Ascorbic Acid; Diet; Diet Records; Female; Humans; Hypertension, Pregnancy-Induced; Pregnancy; Pregnancy Outcome; Prospective Studies; Vitamin E