Cochrane Database Syst Rev. 2009 Oct 7;(4):CD004736.
Effects and safety of preventive oral iron or iron+folic acid supplementation for women during pregnancy.
Reduction of Micronutrient Malnutrition Unit, Department of Nutrition for Health and Development, World Health Organization, 20 Avenue Appia, Geneva 27, Switzerland, 1211.
BACKGROUND: Intake of supplements containing iron or a combination of iron and folic acid by pregnant women may improve maternal health and pregnancy outcomes. Recently, intermittent supplementation regimens have been proposed as alternatives to daily regimens. OBJECTIVES: To assess the effectiveness and safety of daily and intermittent use of iron or iron+folic acid supplements by pregnant women. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (March 2009) and contacted relevant organisations for the identification of ongoing and unpublished studies. SELECTION CRITERIA: All randomised or quasi-randomised trials evaluating the effect of supplementation with iron or iron+folic acid during pregnancy. DATA COLLECTION AND ANALYSIS: We assessed the methodological quality of trials using the standard Cochrane criteria. Two authors independently assessed which trials to include in the review and one author extracted data. MAIN RESULTS: We included 49 trials, involving 23,200 pregnant women. Overall, the results showed significant heterogeneity across most prespecified outcomes and were analysed assuming random-effects. The trials provided limited information related to clinical maternal and infant outcomes.Overall, daily iron supplementation was associated with increased haemoglobin levels in maternal blood both before and after birth and reduced risk of anaemia at term. These effects did not differ significantly between women receiving intermittent or daily iron or iron+folic acid supplementation. Women who received daily prenatal iron supplementation with or without folic acid were less likely to have iron deficiency at term as defined by current cut-off values than those who received no treatment or placebo. Side effects and haemoconcentration (a haemoglobin level greater than 130 g/L) were more common among women who received daily iron or iron+folic acid supplementation than among those who received no treatment or placebo. The risk of haemoconcentration during the second and third trimester was higher among those on a daily regimen of iron supplementation. The clinical significance of haemoconcentration remains uncertain. AUTHORS’ CONCLUSIONS: Universal prenatal supplementation with iron or iron+folic acid provided either daily or weekly is effective to prevent anaemia and iron deficiency at term. We found no evidence, however, of the significant reduction in substantive maternal and neonatal adverse clinical outcomes (low birthweight, delayed development, preterm birth, infection, postpartum haemorrhage). Associated side effects and particularly haemoconcentration during pregnancy may suggest the need for revising iron doses and schemes of supplementation during pregnancy and adjust preventive iron supplementation recommendations.
PMID: 19821332
Antioxidants for preventing pre-eclampsia.
Rumbold A, Duley L, Crowther C, Haslam R.
Department of Obstetrics and Gynaecology, University of Adelaide, Women’s and Children’s Hospital, 72 King William Road, North Adelaide, SA, Australia 5006. alice.rumbold@adelaide.edu.au
Update in:
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.
J Am Diet Assoc. 2009 Sep;109(9):1566-75.
Perinatal depression: prevalence, risks, and the nutrition link–a review of the literature.
Community Health Sciences, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada. bleun@ucalgary.ca
The purpose of this review is to examine the role of nutrition in perinatal depression. Perinatal (maternal) depression refers to major and minor episodes during pregnancy (termed antenatal) and/or within the first 12 months after delivery (termed postpartum or postnatal). Prevalence of antenatal depression can be as high as 20%, while approximately 12% to 16% of women experience postpartum depression. These are probably conservative estimates, as cases of maternal depression are underreported or underdiagnosed. Risk factors for depression include genetic predisposition and environmental factors, as well as a number of social, psychological, and biological factors. One biological factor given increasing consideration is inadequate nutrition. Credible links between nutrient deficiency and mood have been reported for folate, vitamin B-12, calcium, iron, selenium, zinc, and n-3 fatty acids. For maternal depression, the nutrient that has received the most attention from nutrition researchers has been the n-3 essential fatty acids. Numerous studies, such as randomized controlled trials, cohort studies, and ecological studies, have found a positive association between low n-3 levels and a higher incidence of maternal depression. In addition, nutrient inadequacies in pregnant women who consume a typical western diet might be much more common than researchers and clinicians realize. A number of studies have reported inadequate intakes of n-3, folate, B vitamins, iron, and calcium in pregnant women. Depletion of nutrient reserves throughout pregnancy can increase a woman’s risk for maternal depression.
PMID: 19699836
Br J Nutr. 2008 Aug;100(2):278-82.
Feeding pregnant rats a protein-restricted diet persistently alters the methylation of specific cytosines in the hepatic PPAR alpha promoter of the offspring.
Lillycrop KA, Phillips ES, Torrens C, Hanson MA, Jackson AA, Burdge GC.
Development and Cell Biology, Biomedical Sciences Building, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, UK.
Induction of an altered phenotype by prenatal under-nutrition involves changes in the epigenetic regulation of specific genes. We investigated the effect of feeding pregnant rats a protein-restricted (PR) diet with different amounts of folic acid on the methylation of individual CpG dinucleotides in the hepatic PPAR alpha promoter in juvenile offspring, and the effect of the maternal PR diet on CpG methylation in adult offspring. Pregnant rats (five per group) were fed 180 g/kg casein (control) or 90 g/kg casein with 1 mg/kg folic acid (PR), or 90 g/kg casein and 5 mg/kg folic acid (PRF). Offspring were killed on postnatal day 34 (five males and females per group) and day 80 (five males per group). Methylation of sixteen CpG dinucleotides in the PPAR alpha promoter was measured by pyrosequencing. Mean PPAR alpha promoter methylation in the PR offspring (4.5 %) was 26 % lower than controls (6.1 %) due to specific reduction at CpG dinucleotides 2 (40 %), 3 (43 %), 4 (33 %) and 16 (48 %) (P < 0.05). There was no significant difference in methylation at these CpG between control and PRF offspring. Methylation of CpG 5 and 8 was higher (47 and 63 %, respectively, P < 0.05) in the PRF offspring than control or PR offspring. The methylation pattern in day 80 PR offspring was comparable to day 34 PR offspring. These data show for the first time that prenatal nutrition induces differential changes to the methylation of individual CpG dinucleotides in juvenile rats which persist in adults.
PMID: 18186951 [PubMed – indexed for MEDLINE
J Anim Sci. 2009 Oct 23. [Epub ahead of print]
Impacts of amino acid nutrition on pregnancy outcome in pigs: mechanisms and implications for swine production.
Wu G, Bazer FW, Burghardt RC, Johnson GA, Kim SW, Li XL, Satterfield MC, Spencer TE.
Departments of Animal Science and of Veterinary Integrative Biosciences, Texas A&M University, College Station 77843.
Pigs suffer up to 50% embryonic and fetal loss during gestation and exhibit the most severe naturally occurring intrauterine growth retardation among livestock species. Placental insufficiency is a major factor contributing to suboptimal reproductive performance and low birth weights of pigs. Enhancement of placental growth and function through nutritional management offers an effective solution to improving embryonic and fetal survival and growth. We discovered an unusual abundance of the arginine family of AA in porcine allantoic fluid (a reservoir of nutrients) during early gestation when placental growth is most rapid. Arginine is metabolized to ornithine, proline, and nitric oxide, and these compounds possess a plethora of physiological functions. Importantly, nitric oxide is a vasodilator and angiogenic factor, whereas both ornithine and proline are substrates for placental synthesis of polyamines that are key regulators of protein synthesis and angiogenesis. Additionally, arginine, leucine, glutamine, and proline activate the mammalian target of rapamycin cell signaling pathway to enhance protein synthesis and cell proliferation in placentae. To translate basic research on AA biochemistry and nutrition into application, dietary supplementation with 0.83% L-arginine to gilts on d 14 to 28 or d 30 to 114 of gestation increased the number and litter birth weight of live-born piglets. Also, supplementing the gestation diet with 0.4% L-arginine plus 0.6% L-glutamine enhanced efficiency of nutrient utilization, reduced variation in piglet birth weight, and increased litter birth weight. By regulating syntheses of nitric oxide, polyamines and proteins, functional AA stimulate placental growth and the transfer of nutrients from mother to embryo/fetus to promote conceptus survival, growth and development.
PMID: 19854987
J Nutr Biochem. 2009 Dec;20(12):917-26. Epub 2009 Sep 4.
DNA methylation, an epigenetic mechanism connecting folate to healthy embryonic development and aging.
Vitamins and Carcinogenesis Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA.
Experimental studies demonstrated that maternal exposure to certain environmental and dietary factors during early embryonic development can influence the phenotype of offspring as well as the risk of disease development at the later life. DNA methylation, an epigenetic phenomenon, has been suggested as a mechanism by which maternal nutrients affect the phenotype of their offspring in both honeybee and agouti mouse models. Phenotypic changes through DNA methylation can be linked to folate metabolism by the knowledge that folate, a coenzyme of one-carbon metabolism, is directly involved in methyl group transfer for DNA methylation. During the fetal period, organ-specific DNA methylation patterns are established through epigenetic reprogramming. However, established DNA methylation patterns are not immutable and can be modified during our lifetime by the environment. Aberrant changes in DNA methylation with diet may lead to the development of age-associated diseases including cancer. It is also known that the aging process by itself is accompanied by alterations in DNA methylation. Diminished activity of DNA methyltransferases (Dnmts) can be a potential mechanism for the decreased genomic DNA methylation during aging, along with reduced folate intake and altered folate metabolism. Progressive hypermethylation in promoter regions of certain genes is observed throughout aging, and repression of tumor suppressors induced by this epigenetic mechanism appears to be associated with cancer development. In this review, we address the effect of folate on early development and aging through an epigenetic mechanism, DNA methylation.
PMID: 19733471