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Diagnosis and treatment of iron-deficiency anemia in gastrointestinal bleeding: A systematic review.World Journal of Gastroenterology Dec 2020Anemia is considered a public health issue and is often caused by iron deficiency. Iron-deficiency anemia (IDA) often originates from blood loss from lesions in the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Anemia is considered a public health issue and is often caused by iron deficiency. Iron-deficiency anemia (IDA) often originates from blood loss from lesions in the gastrointestinal tract in men and postmenopausal women, and its prevalence among patients with gastrointestinal bleeding has been estimated to be 61%. However, few guidelines regarding the appropriate investigation of patients with IDA due to gastrointestinal bleeding have been published.
AIM
To review current evidence and guidelines concerning IDA management in gastrointestinal bleeding patients to develop recommendations for its diagnosis and therapy.
METHODS
Five gastroenterology experts formed the Digestive Bleeding and Anemia Workgroup and conducted a systematic literature search in PubMed and professional association websites. MEDLINE ( PubMed) searches combined medical subject headings (MeSH) terms and the keywords "gastrointestinal bleeding" with "iron-deficiency anemia" and "diagnosis" or "treatment" or "management" or "prognosis" or "prevalence" or "safety" or "iron" or "transfusion" or "quality of life", or other terms to identify relevant articles reporting the management of IDA in patients over the age of 18 years with gastrointestinal bleeding; retrieved studies were published in English between January 2003 and April 2019. Worldwide professional association websites were searched for clinical practice guidelines. Reference lists from guidelines were reviewed to identify additional relevant articles. The recommendations were developed by consensus during two meetings and were supported by the published literature identified during the systematic search.
RESULTS
From 494 Literature citations found during the initial literature search, 17 original articles, one meta-analysis, and 13 clinical practice guidelines were analyzed. Based on the published evidence and clinical experience, the workgroup developed the following ten recommendations for the management of IDA in patients with gastrointestinal bleeding: (1) Evaluation of hemoglobin and iron status; (2) Laboratory testing; (3) Target treatment population identification; (4) Indications for erythrocyte transfusion; (5) Treatment targets for erythrocyte transfusion; (6) Indications for intravenous iron; (7) Dosages; (8) Monitoring; (9) Indications for intravenous ferric carboxymaltose treatment; and (10) Treatment targets and monitoring of patients. The workgroup also proposed a summary algorithm for the diagnosis and treatment of IDA in patients with acute or chronic gastrointestinal bleeding, which should be implemented during the hospital stay and follow-up visits after patient discharge.
CONCLUSION
These recommendations may serve as a starting point for clinicians to better diagnose and treat IDA in patients with gastrointestinal bleeding, which ultimately may improve health outcomes in these patients.
Topics: Adult; Anemia; Anemia, Iron-Deficiency; Female; Gastrointestinal Hemorrhage; Hemoglobins; Humans; Iron; Male; Middle Aged
PubMed: 33362380
DOI: 10.3748/wjg.v26.i45.7242 -
Nutrients Jul 2022Pregnant women are among the population groups most vulnerable to the development of anemia, as the overall iron requirement during pregnancy is significantly higher... (Review)
Review
Pregnant women are among the population groups most vulnerable to the development of anemia, as the overall iron requirement during pregnancy is significantly higher than in non-pregnant women. The aim of the systematic review was to assess the effectiveness of dietary interventions in the prevention and treatment of iron-deficiency anemia in pregnant women based on randomized-controlled trials. The systematic review was based on the PRISMA guidelines and is registered in the PROSPERO database (CRD42021261235). The search was conducted within PubMed and Web of Science databases for the period until June 2021. The included randomized controlled trials presented effectiveness of dietary interventions in prevention and treatment of iron-deficiency anemia in pregnant women. From the total number of 7825 screened records, the final number of seven studies were included in the systematic review. The procedure of screening, inclusion, reporting, and assessment of the risk of bias while using the revised Cochrane risk of bias tool for randomized trials was conducted by two independent researchers. The studies included in the systematic review were conducted in populations of anemic pregnant women, or mixed populations of anemic and non-anemic pregnant women. The interventions described within the studies were associated with including fortified products, regular products, or dietary counselling. They were based on providing an increased amount of iron, providing an increased amount of multiple nutrients, or general counselling only, while effectiveness was compared with effectiveness of the placebo, supplementation, or control group. The study duration was diversified from a few weeks to half a year or longer. The major biochemical measure assessed within the included studies was hemoglobin. All applied dietary interventions, based on providing increased amount of iron, providing increased amount of multiple nutrients, or general counselling only, were effective. The majority of included studies were assessed as ones of a medium risk of bias. For some studies a high risk of bias was indicated, which resulted from a risk of bias arising from the randomization process, due to deviations from the intended interventions, and in selection of the reported result. Considering this fact, more randomized controlled trials should be planned and conducted in a rigorous manner to confirm the formulated observations of effectiveness of the studied interventions based on providing an increased amount of iron, providing an increased amount of multiple nutrients, or general counselling only.
Topics: Anemia; Anemia, Iron-Deficiency; Dietary Supplements; Female; Food, Fortified; Humans; Iron; Pregnancy; Pregnant Women; Randomized Controlled Trials as Topic
PubMed: 35893877
DOI: 10.3390/nu14153023 -
Ciencia & Saude Coletiva Apr 2018This study aimed to review food and nutrition insecurity indicators associated with iron deficiency anemia in Brazilian children below 5 years. We searched in electronic... (Review)
Review
This study aimed to review food and nutrition insecurity indicators associated with iron deficiency anemia in Brazilian children below 5 years. We searched in electronic databases (SciELO, Lilacs, and Medline) and selected studies by titles, abstracts and full-text reading. Of the 1,023 studies analyzed, 11 fit the inclusion criteria. The results of the studies evidenced that iron deficiency anemia in Brazilian children was associated with sociodemographic and health indicators (male, age below 24 months, children of adolescent mothers, respiratory infections, diarrhea, low maternal schooling, parents' working conditions, nursery time, lack of basic sanitation, maternal anemia, lack of ferrous sulfate use by the mother and/or child and late onset of prenatal care), nutritional indicators (low birth weight, diet characteristics, such as the habit of milk consumption close to meals, low exclusive and full breastfeeding time) and economic indicators (low per capita income). The food and nutrition insecurity analyzed in this study from the perspective of different indicators is associated with iron deficiency anemia in children under 5 years in Brazil.
Topics: Anemia, Iron-Deficiency; Brazil; Child, Preschool; Diet; Food Supply; Humans; Infant; Nutritional Status; Socioeconomic Factors
PubMed: 29694583
DOI: 10.1590/1413-81232018234.16012016 -
Nutrition Reviews Jul 2023Iron deficiency and anemia have serious consequences, especially for children and pregnant women. Iron salts are commonly provided as oral supplements to prevent and... (Meta-Analysis)
Meta-Analysis
The effects of oral ferrous bisglycinate supplementation on hemoglobin and ferritin concentrations in adults and children: a systematic review and meta-analysis of randomized controlled trials.
CONTEXT
Iron deficiency and anemia have serious consequences, especially for children and pregnant women. Iron salts are commonly provided as oral supplements to prevent and treat iron deficiency, despite poor bioavailability and frequently reported adverse side effects. Ferrous bisglycinate is a novel amino acid iron chelate that is thought to be more bioavailable and associated with fewer gastrointestinal (GI) adverse events as compared with iron salts.
OBJECTIVE
A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to evaluate the effects of ferrous bisglycinate supplementation compared with other iron supplements on hemoglobin and ferritin concentrations and GI adverse events.
DATA SOURCES
A systematic search of electronic databases and grey literature was performed up to July 17, 2020, yielding 17 RCTs that reported hemoglobin or ferritin concentrations following at least 4 weeks' supplementation of ferrous bisglycinate compared with other iron supplements in any dose or frequency.
DATA EXTRACTION
Random-effects meta-analyses were conducted among trials of pregnant women (n = 9) and children (n = 4); pooled estimates were expressed as standardized mean differences (SMDs). Incidence rate ratios (IRRs) were estimated for GI adverse events, using Poisson generalized linear mixed-effects models. The remaining trials in other populations (n = 4; men and nonpregnant women) were qualitatively evaluated.
DATA ANALYSIS
Compared with other iron supplements, supplementation with ferrous bisglycinate for 4-20 weeks resulted in higher hemoglobin concentrations in pregnant women (SMD, 0.54 g/dL; 95% confidence interval [CI], 0.15-0.94; P < 0.01) and fewer reported GI adverse events (IRR, 0.36; 95%CI, 0.17-0.76; P < 0.01). We observed a non-significant trend for higher ferritin concentrations in pregnant women supplemented with ferrous bisglycinate. No significant differences in hemoglobin or ferritin concentrations were detected among children.
CONCLUSION
Ferrous bisglycinate shows some benefit over other iron supplements in increasing hemoglobin concentration and reducing GI adverse events among pregnant women. More trials are needed to assess the efficacy of ferrous bisglycinate against other iron supplements in other populations.
PROSPERO REGISTRATION NO
CRD42020196984.
Topics: Adult; Child; Female; Humans; Male; Pregnancy; Anemia, Iron-Deficiency; Dietary Supplements; Ferritins; Hemoglobins; Iron; Iron Deficiencies; Randomized Controlled Trials as Topic; Salts; Ferrous Compounds
PubMed: 36728680
DOI: 10.1093/nutrit/nuac106 -
PloS One 2022A wealth of human and experimental studies document a causal and aggravating role of iron deficiency in neurodevelopmental disorders. While pre-, peri-, and early...
BACKGROUND
A wealth of human and experimental studies document a causal and aggravating role of iron deficiency in neurodevelopmental disorders. While pre-, peri-, and early postnatal iron deficiency sets the stage for the risk of developing neurodevelopmental disorders, iron deficiency acquired at later ages aggravates pre-existing neurodevelopmental disorders. Yet, the association of iron deficiency and neurodevelopmental disorders in childhood and adolescence has not yet been explored comprehensively. In this scoping review, we investigate 1) the association of iron deficiency in children and adolescents with the most frequent neurodevelopmental disorders, ADHD, ASD, and FASD, and 2) whether iron supplementation improves outcomes in these disorders.
METHOD
Scoping review of studies published between 1994 and 2021 using "iron deficiency / iron deficiency anemia" AND "ADHD" OR "autism" OR "FASD" in four biomedical databases. The main inclusion criterion was that articles needed to have quantitative determination of iron status at any postnatal age with primary iron markers such as serum ferritin being reported in association with ADHD, ASD, or FASD.
RESULTS
For ADHD, 22/30 studies and 4/4 systematic reviews showed an association of ADHD occurrence or severity with iron deficiency; 6/6 treatment studies including 2 randomized controlled trials demonstrated positive effects of iron supplementation. For ASD, 3/6 studies showed an association with iron deficiency, while 3/6 and 1/1 systematic literature review did not; 4 studies showed a variety of prevalence rates of iron deficiency in ASD populations; 1 randomized controlled trial found no positive effect of iron supplementation on behavioural symptoms of ASD. For FASD, 2/2 studies showed an association of iron deficiency with growth retardation in infants and children with prenatal alcohol exposure.
CONCLUSION
Evidence in favor of screening for iron deficiency and using iron supplementation for pediatric neurodevelopmental disorders comes primarily from ADHD studies and needs to be further investigated for ASD and FASD. Further analysis of study methodologies employed and populations investigated is needed to compare studies against each other and further substantiate the evidence created.
Topics: Adolescent; Anemia, Iron-Deficiency; Child; Female; Ferritins; Humans; Infant; Iron; Iron Deficiencies; Neurodevelopmental Disorders; Pregnancy; Prenatal Exposure Delayed Effects; Randomized Controlled Trials as Topic
PubMed: 36173945
DOI: 10.1371/journal.pone.0273819 -
Nutrients Jan 2022In adolescents, iron-deficiency anemia is the leading cause of disability-adjusted life years lost. The World Health Organization recommends delivering iron...
In adolescents, iron-deficiency anemia is the leading cause of disability-adjusted life years lost. The World Health Organization recommends delivering iron supplementation through school-based platforms, requiring partnerships with the education sector. This anemia-reduction intervention is valued for the perceived benefits of improved learning and school performance. This article aims to systematically review the available evidence on the relationship between iron status and anemia and impacts of iron interventions on cognitive and academic performance in adolescents. Fifty studies were included: = 26 cross-sectional and = 24 iron-containing interventions. Our review suggests that iron status and anemia may be associated with academic performance in some contexts and that iron supplementation during adolescence may improve school performance, attention, and concentration. However, nearly all supplementation trials were judged to have moderate or high risk of bias. We did not find evidence suggesting that iron status and anemia influenced or were associated with attention, intelligence, nor memory in adolescents. Further, iron supplementation did not improve memory and recall or intelligence. Overall, more high-quality research is needed to guide programmers and policy makers to understand the relationships between anemia and educational performance and the potential impacts of iron interventions, which effectively reduce anemia, on adolescents' learning and school performance.
Topics: Academic Performance; Adolescent; Anemia, Iron-Deficiency; Cognition; Cross-Sectional Studies; Dietary Supplements; Disability-Adjusted Life Years; Female; Humans; Iron; Male; Nutritional Status
PubMed: 35011099
DOI: 10.3390/nu14010224 -
The Cochrane Database of Systematic... Sep 2021Anaemia is a prevalent health problem worldwide. Some types are preventable or controllable with iron supplementation (pills or drops), fortification (sprinkles or... (Review)
Review
BACKGROUND
Anaemia is a prevalent health problem worldwide. Some types are preventable or controllable with iron supplementation (pills or drops), fortification (sprinkles or powders containing iron added to food) or improvements to dietary diversity and quality (e.g. education or counselling).
OBJECTIVES
To summarise the evidence from systematic reviews regarding the benefits or harms of nutrition-specific interventions for preventing and controlling anaemia in anaemic or non-anaemic, apparently healthy populations throughout the life cycle.
METHODS
In August 2020, we searched MEDLINE, Embase and 10 other databases for systematic reviews of randomised controlled trials (RCTs) in anaemic or non-anaemic, apparently healthy populations. We followed standard Cochrane methodology, extracting GRADE ratings where provided. The primary outcomes were haemoglobin (Hb) concentration, anaemia, and iron deficiency anaemia (IDA); secondary outcomes were iron deficiency (ID), severe anaemia and adverse effects (e.g. diarrhoea, vomiting).
MAIN RESULTS
We included 75 systematic reviews, 33 of which provided GRADE assessments; these varied between high and very low. Infants (6 to 23 months; 13 reviews) Iron supplementation increased Hb levels and reduced the risk of anaemia and IDA in two reviews. Iron fortification of milk or cereals, multiple-micronutrient powder (MMNP), home fortification of complementary foods, and supplementary feeding increased Hb levels and reduced the risk of anaemia in six reviews. In one review, lipid-based nutrient supplementation (LNS) reduced the risk of anaemia. In another, caterpillar cereal increased Hb levels and IDA prevalence. Food-based strategies (red meat and fortified cow's milk, beef) showed no evidence of a difference (1 review). Preschool and school-aged children (2 to 10 years; 8 reviews) Daily or intermittent iron supplementation increased Hb levels and reduced the risk of anaemia and ID in two reviews. One review found no evidence of difference in Hb levels, but an increased risk of anaemia and ID for the intermittent regime. All suggested that zinc plus iron supplementation versus zinc alone, multiple-micronutrient (MMN)-fortified beverage versus control, and point-of-use fortification of food with iron-containing micronutrient powder (MNP) versus placebo or no intervention may increase Hb levels and reduce the risk of anaemia and ID. Fortified dairy products and cereal food showed no evidence of a difference on the incidence of anaemia (1 review). Adolescent children (11 to 18 years; 4 reviews) Compared with no supplementation or placebo, five types of iron supplementation may increase Hb levels and reduce the risk of anaemia (3 reviews). One review on prevention found no evidence of a difference in anaemia incidence on iron supplementation with or without folic acid, but Hb levels increased. Another suggested that nutritional supplementation and counselling reduced IDA. One review comparing MMN fortification with no fortification observed no evidence of a difference in Hb levels. Non-pregnant women of reproductive age (19 to 49 years; 5 reviews) Two reviews suggested that iron therapy (oral, intravenous (IV), intramuscular (IM)) increased Hb levels; one showed that iron folic acid supplementation reduced anaemia incidence; and another that daily iron supplementation with or without folic acid or vitamin C increased Hb levels and reduced the risk of anaemia and ID. No review reported interventions related to fortification or dietary diversity and quality. Pregnant women of reproductive age (15 to 49 years; 23 reviews) One review apiece suggested that: daily iron supplementation with or without folic acid increased Hb levels in the third trimester or at delivery and in the postpartum period, and reduced the risk of anaemia, IDA and ID in the third trimester or at delivery; intermittent iron supplementation had no effect on Hb levels and IDA, but increased the risk of anaemia at or near term and ID, and reduced the risk of side effects; vitamin A supplementation alone versus placebo, no intervention or other micronutrient might increase maternal Hb levels and reduce the risk of maternal anaemia; MMN with iron and folic acid versus placebo reduced the risk of anaemia; supplementation with oral bovine lactoferrin versus oral ferrous iron preparations increased Hb levels and reduced gastrointestinal side effects; MNP for point-of-use fortification of food versus iron and folic acid supplementation might decrease Hb levels at 32 weeks' gestation and increase the risk of anaemia; and LNS versus iron or folic acid and MMN increased the risk of anaemia. Mixed population (all ages; 22 reviews) Iron supplementation versus placebo or control increased Hb levels in healthy children, adults, and elderly people (4 reviews). Hb levels appeared to increase and risk of anaemia and ID decrease in two reviews investigating MMN fortification versus placebo or no treatment, iron fortified flour versus control, double fortified salt versus iodine only fortified salt, and rice fortification with iron alone or in combination with other micronutrients versus unfortified rice or no intervention. Each review suggested that fortified versus non-fortified condiments or noodles, fortified (sodium iron ethylenediaminetetraacetate; NaFeEDTA) versus non-fortified soy sauce, and double-fortified salt versus control salt may increase Hb concentration and reduce the risk of anaemia. One review indicated that Hb levels increased for children who were anaemic or had IDA and received iron supplementation, and decreased for those who received dietary interventions. Another assessed the effects of foods prepared in iron pots, and found higher Hb levels in children with low-risk malaria status in two trials, but no difference when comparing food prepared in non-cast iron pots in a high-risk malaria endemicity mixed population. There was no evidence of a difference for adverse effects. Anaemia and malaria prevalence were rarely reported. No review focused on women aged 50 to 65 years plus or men (19 to 65 years plus).
AUTHORS' CONCLUSIONS
Compared to no treatment, daily iron supplementation may increase Hb levels and reduce the risk of anaemia and IDA in infants, preschool and school-aged children and pregnant and non-pregnant women. Iron fortification of foods in infants and use of iron pots with children may have prophylactic benefits for malaria endemicity low-risk populations. In any age group, only a limited number of reviews assessed interventions to improve dietary diversity and quality. Future trials should assess the effects of these types of interventions, and consider the requirements of different populations.
Topics: Adolescent; Adult; Aged; Anemia; Anemia, Iron-Deficiency; Animals; Child; Dietary Supplements; Female; Food, Fortified; Humans; Iron; Life Cycle Stages; Male; Micronutrients; Middle Aged; Pregnancy; Systematic Reviews as Topic; Young Adult
PubMed: 34564844
DOI: 10.1002/14651858.CD013092.pub2 -
Asia Pacific Journal of Clinical... 2020Nutritional anemia in Indonesian children and adolescents is generally regarded and treated as iron-deficient anemia, as it is in individuals in other age groups.
BACKGROUND
Nutritional anemia in Indonesian children and adolescents is generally regarded and treated as iron-deficient anemia, as it is in individuals in other age groups.
OBJECTIVES
Yet, it remains a public health threat without comprehensive management or a sustained solution.
METHODS
This review seeks to improve understanding of impediments to its resolution. Relevant studies reported in the past 5 years were identified in PubMed, Science Direct, Crossreff, Google Scholar, and Directory of Open Access Journals databases.
RESULTS
In all, 12 studies in several Indonesian cities provided the basis for the review. Most were conducted in schools, indicating the potential of these institutions as targets for intervention but pointing to serious deficiencies in identification of the problem across the archipelago and in remote and rural areas. No study has evaluated coexistent anemia and malnutrition, which likely would have revealed the multi-factoriality of nutritional anemia. Data regarding nutrition education, food-based innovation, and supplementation, which may alleviate anemia in children and adolescents, are available, although study lengths and sample sizes have limited interpretation and comparison.
CONCLUSIONS
Broadly, three intervention approaches to nutritional anemia have been undertaken, namely food-based interventions, nutrient supplementation, and nutrition education. Some progress has been made with these approaches, presumably through increases in iron intake. More information is needed regarding the underlying causality and pathogenesis, suboptimal food patterns, and comorbidities, any of which might limit the effectiveness of programs designed to resolve childhood and adolescent anemia in Indonesia.
Topics: Adolescent; Adolescent Health; Anemia; Anemia, Iron-Deficiency; Child; Child Health; Child, Preschool; Dietary Supplements; Feeding Behavior; Female; Food Supply; Health Education; Humans; Indonesia; Infant; Iron; Iron Deficiencies; Male; Malnutrition; Nutritional Status; Reproducibility of Results; Rural Population; Trace Elements
PubMed: 33377744
DOI: 10.6133/apjcn.202012_29(S1).03 -
American Journal of Obstetrics and... Jul 2019To perform a systematic review of randomized trials comparing oral vs intravenous (IV) iron therapy to treat postpartum anemia.
OBJECTIVE
To perform a systematic review of randomized trials comparing oral vs intravenous (IV) iron therapy to treat postpartum anemia.
DATA SOURCES
Data sources were as follows: PubMed (1972-2017); Cochrane Central Register of Controlled Trials, CENTRAL (1972-2017); CINAHL (1972-2017); Web of Science; Excerpta Medica Database, and EMBASE (1972-2017).
STUDY ELIGIBILITY CRITERIA
We included randomized trials comparing oral vs IV iron monotherapy to treat postpartum anemia (classified as a hemoglobin <12 g/dL).
STUDY APPRAISAL AND SYNTHESIS METHODS
Study quality was assessed with the Cochrane risk of bias assessment tool. The primary outcome was hemoglobin concentration at 6 weeks postpartum. Secondary outcomes included hemoglobin concentration at 1-5 weeks postpartum, ferritin concentration at 1-6 weeks postpartum, and maternal adverse outcomes. For meta-analysis, mean differences and odds ratios using a random effects model were calculated. Risk of heterogeneity was reported as I.
RESULTS
A total of 15 randomized trials met our inclusion criteria (n = 1001 and 1 181 women receiving oral iron and IV iron, respectively); 4 studies reported data for our primary outcome. We observed higher postpartum week 6 hemoglobin concentrations in the IV iron group compared to the oral iron group (mean difference, 0.9 g/dL; 95% confidence interval (CI), 0.4-1.3; P = .0003). Compared to oral iron, women receiving IV iron had higher hemoglobin concentrations at postpartum weeks 1, 2, and 3; higher ferritin concentrations at postpartum weeks 1, 2, 4, and 6; an increased likelihood of skin flushing (odds ratio [OR], 6.95; 95% CI, 1.56-31.03; P = .01; I = 0%); and a decreased likelihood of constipation (OR, 0.08; 95% CI, 0.03-0.21; P < .00001, I = 27%) and dyspepsia (OR, 0.07; 95% confidence interval, 0.01-0.42; P = .004; I = 0%). The reported event rate for anaphylaxis among women receiving IV iron was 0.6%.
CONCLUSION
In this systematic review, among women with postpartum anemia, hemoglobin concentrations at 6 weeks postpartum were almost 1 g/dL higher in women who received IV iron compared to oral iron. The safety profile of IV iron was also reassuring. Given the weaker hemoglobin response and higher risk of gastrointestinal side effects with oral iron use, our findings suggest that IV iron be considered as a viable treatment option for postpartum iron deficiency anemia.
Topics: Administration, Intravenous; Administration, Oral; Anemia, Iron-Deficiency; Female; Ferric Compounds; Ferrous Compounds; Hematinics; Hemoglobins; Humans; Iron; Pregnancy; Puerperal Disorders; Treatment Outcome
PubMed: 30578747
DOI: 10.1016/j.ajog.2018.12.016 -
The Cochrane Database of Systematic... Jul 2015Iron and folic acid supplementation has been the preferred intervention to improve iron stores and prevent anaemia among pregnant women, and it is thought to improve... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Iron and folic acid supplementation has been the preferred intervention to improve iron stores and prevent anaemia among pregnant women, and it is thought to improve other maternal and birth outcomes.
OBJECTIVES
To assess the effects of daily oral iron supplements for pregnant women, either alone or in conjunction with folic acid, or with other vitamins and minerals as a public health intervention in antenatal care.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (10 January 2015). We also searched the WHO International Clinical Trials Registry Platform (ICTRP) (26 February 2015) and contacted relevant organisations for the identification of ongoing and unpublished studies (26 February 2015) .
SELECTION CRITERIA
Randomised or quasi-randomised trials evaluating the effects of oral preventive supplementation with daily iron, iron + folic acid or iron + other vitamins and minerals during pregnancy.
DATA COLLECTION AND ANALYSIS
We assessed the methodological quality of trials using standard Cochrane criteria. Two review authors independently assessed trial eligibility, extracted data and conducted checks for accuracy. We used the GRADE approach to assess the quality of the evidence for primary outcomes.We anticipated high heterogeneity among trials and we pooled trial results using a random-effects model and were cautious in our interpretation of the pooled results: the random-effects model gives the average treatment effect.
MAIN RESULTS
We included 61 trials. Forty-four trials, involving 43,274 women, contributed data and compared the effects of daily oral supplements containing iron versus no iron or placebo.Preventive iron supplementation reduced maternal anaemia at term by 70% (risk ratio (RR) 0.30; 95% confidence interval (CI) 0.19 to 0.46, 14 trials, 2199 women, low quality evidence), iron-deficiency anaemia at term (RR 0.33; 95% CI 0.16 to 0.69, six trials, 1088 women), and iron deficiency at term by 57% (RR 0.43; 95% CI 0.27 to 0.66, seven trials, 1256 women, low quality evidence). There were no clear differences between groups for severe anaemia in the second or third trimester, or maternal infection during pregnancy (RR 0.22; 95% CI 0.01 to 3.20, nine trials, 2125 women, very low quality evidence; and, RR 1.21; 95% CI 0.33 to 4.46; one trial, 727 women, low quality evidence, respectively), or maternal mortality (RR 0.33; 95% CI 0.01 to 8.19, two trials, 12,560 women, very low quality evidence), or reporting of side effects (RR 1.29; 95% CI 0.83 to 2.02, 11 trials, 2423 women, very low quality evidence). Women receiving iron were on average more likely to have higher haemoglobin (Hb) concentrations at term and in the postpartum period, but were at increased risk of Hb concentrations greater than 130 g/L during pregnancy, and at term.Compared with controls, women taking iron supplements less frequently had low birthweight newborns (8.4% versus 10.3%, average RR 0.84; 95% CI 0.69 to 1.03, 11 trials, 17,613 women, low quality evidence), and preterm babies (RR 0.93; 95% CI 0.84 to 1.03, 13 trials, 19,286 women, moderate quality evidence). They appeared to also deliver slightly heavier babies (mean difference (MD) 23.75; 95% CI -3.02 to 50.51, 15 trials, 18,590 women, moderate quality evidence). None of these results were statistically significant. There were no clear differences between groups for neonatal death (RR 0.91; 95% CI 0.71 to 1.18, four trials, 16,603 infants, low quality evidence), or congenital anomalies (RR 0.88, 95% CI 0.58 to 1.33, four trials, 14,636 infants, low quality evidence).Twenty-three studies were conducted in countries that in 2011 had some malaria risk in parts of the country. In some of these countries/territories, malaria is present only in certain areas or up to a particular altitude. Only two of these studies reported malaria outcomes. There is no evidence that iron supplementation increases placental malaria. For some outcomes heterogeneity was higher than 50%.
AUTHORS' CONCLUSIONS
Supplementation reduces the risk of maternal anaemia and iron deficiency in pregnancy but the positive effect on other maternal and infant outcomes is less clear. Implementation of iron supplementation recommendations may produce heterogeneous results depending on the populations' background risk for low birthweight and anaemia, as well as the level of adherence to the intervention.
Topics: Anemia, Iron-Deficiency; Dietary Supplements; Female; Folic Acid; Humans; Infant, Low Birth Weight; Infant, Newborn; Iron; Iron, Dietary; Pregnancy; Pregnancy Complications, Hematologic; Pregnancy Outcome; Prenatal Care; Randomized Controlled Trials as Topic
PubMed: 26198451
DOI: 10.1002/14651858.CD004736.pub5