Biomedical subjects

A Rumbold

Publications and source records attributed to A Rumbold.

4 recordsLinked to original sources

PubMed2005

Antioxidants for preventing pre-eclampsia.

BACKGROUND: Oxidative stress has been proposed as a key factor involved in the development of pre-eclampsia. Supplementing women with antioxidants during pregnancy may help to counteract oxidative stress and thereby prevent or delay the onset of pre-eclampsia. OBJECTIVES: To determine the effectiveness and safety of any antioxidant supplementation during pregnancy and the risk of developing pre-eclampsia and its related complications. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group Trials Register (June 2004) and the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2004). SELECTION CRITERIA: All randomised and quasi-randomised trials comparing one or more antioxidants with either placebo or no antioxidants during pregnancy for the prevention of pre-eclampsia, and trials comparing one or more antioxidants with another, or with other interventions. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion, data extraction and trial quality. Data were double-entered into the Review Manager software. MAIN RESULTS: Seven trials involving 6082 women are included in this review. The largest trial (5021 women) was quasi-random and only three of the seven included trials were rated high quality. Supplementing women with any antioxidants during pregnancy compared with control or placebo was associated with a 39% reduction in the risk of pre-eclampsia (relative risk (RR) 0.61, 95% confidence intervals (CI) 0.50 to 0.75, seven trials, 6082 women). Women receiving antioxidants compared with control or placebo also had a reduced risk of having a small-for-gestational-age infant (RR 0.64, 95% CI 0.47 to 0.87, three trials, 634 women), their infants had a greater mean birthweight (weighted mean difference 91.83 g, 95% CI 11.55 to 172.11, three trials, 451 women), but they were more likely to give birth preterm (RR 1.38, 95% CI 1.04 to 1.82, three trials, 583 women). There were insufficient data for reliable conclusions about possible effects on any other outcomes. AUTHORS' CONCLUSIONS: These results should be interpreted with caution, as most of the data come from poor quality studies. Nevertheless, antioxidant supplementation seems to reduce the risk of pre-eclampsia. There also appears to be a reduction in the risk of having a small-for-gestational-age baby associated with antioxidants, although there is an increase in the risk of preterm birth. Several large trials are ongoing, and the results of these are needed before antioxidants can be recommended for clinical practice.

Antioxidants↗

PubMed2005

Vitamin E supplementation in pregnancy.

BACKGROUND: Vitamin E supplementation may help reduce the risk of pregnancy complications involving oxidative stress, such as pre-eclampsia. There is a need to evaluate the efficacy and safety of vitamin E supplementation in pregnancy. OBJECTIVES: To assess the effects of vitamin E supplementation, alone or in combination with other separate supplements, on pregnancy outcomes, adverse events, side-effects and use of health services. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group Trials Register (23 June 2004), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2004), MEDLINE (1966 to May 2004), Current Contents (1998 to May 2004) and EMBASE (1980 to May 2004). SELECTION CRITERIA: All randomised or quasi-randomised controlled trials evaluating vitamin E supplementation in pregnant women. We excluded interventions using a multivitamin supplement that contained vitamin E. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trials for inclusion, extracted data and assessed trial quality. MAIN RESULTS: Four trials, involving 566 women either at high risk of pre-eclampsia or with established pre-eclampsia, were eligible for this review. All trials assessed vitamin E in combination with other supplements and two trials were published in abstract form only. No difference was found between women supplemented with vitamin E in combination with other supplements during pregnancy compared with placebo for the risk of stillbirth (relative risk (RR) was 0.77, 95% confidence intervals (CI) 0.35 to 1.71, two trials, 339 women), neonatal death (RR 5.00, 95% CI 0.64 to 39.06, one trial, 40 women), perinatal death (RR 1.29, 95% CI 0.67 to 2.48, one trial, 56 women), preterm birth (RR 1.29, 95% CI 0.78 to 2.15, two trials, 383 women), intrauterine growth restriction (RR 0.72, 95% CI 0.49 to 1.04, two trials, 383 women) or birthweight (weighted mean difference -139.00 g, 95% CI -517.68 to 239.68, one trial, 100 women), using fixed-effect models. Substantial heterogeneity was found for pre-eclampsia. Women supplemented with vitamin E in combination with other supplements compared with placebo were at decreased risk of developing clinical pre-eclampsia (RR 0.44, 95% CI 0.27 to 0.71, three trials, 510 women) using fixed-effect models; however, this difference could not be demonstrated when using random-effects models (RR 0.44, 95% CI 0.16 to 1.22, three trials, 510 women). There were no differences between women supplemented with vitamin E compared with placebo for any of the secondary outcomes. AUTHORS' CONCLUSIONS: The data are too few to say if vitamin E supplementation either alone or in combination with other supplements is beneficial during pregnancy.

Antioxidants↗

PubMed2005

Vitamin C supplementation in pregnancy.

BACKGROUND: Vitamin C supplementation may help reduce the risk of pregnancy complications like pre-eclampsia, intrauterine growth restriction and maternal anaemia. There is a need to evaluate the efficacy and safety of vitamin C supplementation in pregnancy. OBJECTIVES: To evaluate the effects of vitamin C supplementation, alone or in combination with other separate supplements, on pregnancy outcomes, adverse events, side-effects and use of health resources. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group Trials Register (23 June 2004), Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2004), MEDLINE, Current Contents and EMBASE. SELECTION CRITERIA: All randomised or quasi-randomised controlled trials evaluating vitamin C supplementation in pregnant women. Interventions using a multivitamin supplement containing vitamin C or where the primary supplement was iron were excluded. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trials for inclusion, extracted data and assessed trial quality. MAIN RESULTS: Five trials, involving 766 women, are included in this review. No difference was seen between women supplemented with vitamin C alone or combined with other supplements compared with placebo for the risk of stillbirth (relative risk (RR) 0.87, 95% confidence intervals (CI) 0.41 to 1.87, three trials, 539 women), perinatal death (RR 1.16, 95% CI 0.61 to 2.18, two trials, 238 women), birthweight (weighted mean difference (WMD) -139.00 g, 95% CI -517.68 to 239.68, one trial, 100 women) or intrauterine growth restriction (RR 0.72, 95% CI 0.49 to 1.04, two trials, 383 women). Women supplemented with vitamin C alone or combined with other supplements were at increased risk of giving birth preterm (RR 1.38, 95% CI 1.04 to 1.82, three trials, 583 women). Significant heterogeneity was found for neonatal death and pre-eclampsia. No difference was seen between women supplemented with vitamin C combined with other supplements for the risk of neonatal death (RR 1.73, 95% CI 0.25 to 12.12, two trials, 221 women), using a random-effects model. For pre-eclampsia, women supplemented with vitamin C combined with other supplements were at decreased risk when using a fixed-effect model (RR 0.47, 95% CI 0.30 to 0.75, four trials, 710 women); however, this difference could not be demonstrated when using a random-effects model (RR 0.52, 95% CI 0.23 to 1.20, four trials, 710 women). AUTHORS' CONCLUSIONS: The data are too few to say if vitamin C supplementation, alone or combined with other supplements, is beneficial during pregnancy. Preterm birth may have been increased with vitamin C supplementation.

Ascorbic Acid↗

PubMed2005

Vitamin supplementation for preventing miscarriage.

BACKGROUND: Miscarriage is a common complication of pregnancy that can be caused by a wide range of factors. Poor dietary intake of vitamins has been associated with an increased risk of miscarriage, therefore supplementing women with vitamins either prior to or in early pregnancy may help prevent miscarriage. OBJECTIVES: The objectives of this review are to determine the effectiveness and safety of any vitamin supplementation, on the risk of spontaneous miscarriage, maternal adverse outcomes and fetal and infant adverse outcomes. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group Trials Register (8 September 2004), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003) and MEDLINE (1966 to May 2003), Current Contents (1998 to May 2003) and EMBASE (1980 to May 2003). SELECTION CRITERIA: All randomised and quasi-randomised trials comparing one or more vitamins with either placebo, other vitamins, no vitamins or other interventions, prior to conception, periconceptionally or in early pregnancy (less than 20 weeks' gestation). DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion, extracted data and assessed trial quality. MAIN RESULTS: We identified seventeen trials assessing supplementation with any vitamin(s) starting prior to 20 weeks' gestation and reporting at least one primary outcome that were eligible for the review. Overall, the included trials involved 35,812 women and 37,353 pregnancies. Two trials were cluster randomised and contributed data for 20,758 women and 22,299 pregnancies in total. No difference was seen between women taking any vitamins compared with controls for total fetal loss (relative risk (RR) 1.05, 95% confidence interval (CI) 0.95 to 1.15), early or late miscarriage (RR 1.08, 95% CI 0.95 to 1.24) or stillbirth (RR 0.85, 95% CI 0.63 to 1.14) and most of the other primary outcomes, using fixed-effect models. For the other primary outcomes, women given any type of vitamin(s) compared with controls were less likely to develop pre-eclampsia (RR 0.68, 95% CI 0.54 to 0.85, four trials, 5580 women) and more likely to have a multiple pregnancy (RR 1.38, 95% CI 1.12 to 1.70, three trials, 20,986 women). AUTHORS' CONCLUSIONS: Taking vitamin supplements, alone or in combination with other vitamins, prior to pregnancy or in early pregnancy, does not prevent women experiencing miscarriage or stillbirth. However, women taking vitamin supplements may be less likely to develop pre-eclampsia and more likely to have a multiple pregnancy.

Abortion, Habitual↗