Intermittent oral iron supplementation during pregnancy

Anemia in Pregnancy With CKD

Chronic kidney disease (CKD), anemia, and iron deficiency are global health issues affecting individuals in both high-income and low-income countries. In pregnancy, both CKD and iron deficiency anemia increase the risk of adverse maternal and neonatal outcomes, including increased maternal morbidity and mortality, stillbirth, perinatal death, preterm birth, and low birthweight. However, it is unknown to which extent iron deficiency anemia contributes to adverse outcomes in CKD pregnancy. Furthermore, little is known regarding the prevalence, pathophysiology, and treatment of iron deficiency and anemia in pregnant women with CKD. Therefore, there are many unanswered questions regarding optimal management with oral or i.v. iron and recombinant human erythropoietin (rhEPO) in these women. In this review, we present a short overview of the (patho)physiology of anemia in healthy pregnancy and in people living with CKD. We present an evaluation of the literature on iron deficiency, anemia, and nutritional deficits in pregnant women with CKD; and we evaluate current knowledge gaps. Finally, we propose research priorities regarding anemia in pregnant women with CKD.

Patient Blood Management in Pregnancy

BACKGROUND

Patient blood management (PBM) is a multidisciplinary and patient-centered treatment approach, comprising the detection and treatment of anemia, the minimization of blood loss, and the rational use of allogeneic transfusions. Pregnancy, delivery, and the puerperium are associated with increased rates of iron deficiency and anemia, which correlates with worse maternal and fetal outcomes and places pregnant women at increased risk of obstetric hemorrhage.

SUMMARY

Early screening for iron deficiency before the onset of anemia, as well as the use of oral and intravenous iron to treat iron deficiency anemia, has been shown to be beneficial. Anemia in pregnancy and the puerperium should be treated according to a staged regimen, administering either iron alone or in combination with an off-label use of human recombinant erythropoietin in selected patients. This regimen should be tailored to the needs of each individual patient. Postpartum hemorrhage (PPH) accounts for up to one-third of maternal deaths in both developing and developed countries. Bleeding complications should be anticipated and blood loss reduced by interdisciplinary preventive measures and individually tailored care. It is recommended that facilities have a PPH algorithm, primarily focusing on prevention through use of uterotonics, but also incorporating early diagnosis of the cause of bleeding, optimization of hemostatic conditions, timely administration of tranexamic acid, and integration of point-of-care tests to support the guided substitution of coagulation factors, alongside standard laboratory tests. Additionally, cell salvage has proven beneficial and should be considered for various indications in obstetrics including hematologic disturbances, as well as various forms of placental disorders.

KEY MESSAGE

This article reviews PBM in pregnancy, delivery, and the puerperium. The concept comprises early screening and treatment of anemia and iron deficiency, a transfusion and coagulation algorithm during delivery, as well as cell salvage.

Protocol for a multicenter, double-blinded placebo-controlled randomized controlled trial comparing intravenous ferric derisomaltose to oral ferrous sulfate for the treatment of iron deficiency anemia in pregnancy: The IVIDA2 trial

BACKGROUND

Iron deficiency anemia (IDA) is common during pregnancy and associated with adverse maternal and neonatal outcomes. Treatment with iron supplementation is recommended during pregnancy, but the optimal delivery route is unclear. Oral iron risks has high risk of gastrointestinal side effects and low absorption. Intravenous iron is infused directly but is expensive. The American College of Obstetricians and Gynecologists currently recommends oral iron to treat IDA in pregnancy with intravenous iron reserved as second-line therapy, if needed. This approach is associated with persistent anemia, increasing the risk of peripartum blood transfusion. We aim to provide data on optimal route of iron repletion for IDA in pregnancy.

METHODS

In IVIDA2, a double-blind, placebo controlled, multicenter randomized trial in the United States, 746 pregnant people with moderate-to-severe IDA (hemoglobin <10 g/dL and ferritin <30 ng/mL) at 24-28 weeks' gestation will be randomized 1:1 to either a single 1000 mg dose of intravenous ferric derisomaltose and oral placebo (1-3 times daily) or a single placebo infusion with 1-3 times daily 325 mg ferrous sulfate (65 mg elemental iron) tablet. The primary outcome is peripartum blood transfusion (blood transfusion from delivery to 7 days postpartum). Secondary outcomes include adverse medication reactions, maternal and neonatal hematologic indices, and offspring neurodevelopment.

ETHICS AND DISSEMINATION

A central ethical review board-Advarra-granted ethical approval (Pro00060930). Participating centers-Women & Infants Hospital of Rhode Island, University of Michigan Medical Center, Washington University School of Ethics and dissemination: A central ethical review board-Advarra-granted ethical approval (Pro00060930). Participating centers-Women & Infants Hospital of Rhode Island, University of Michigan Medical Center, Washington University School of.

Protective effect of Beta vulgaris roots supplementation on anemic phenylhydrazine-intoxicated rats

Anemia is a public health problem that affects many people worldwide. Beetroot (Beta vulgaris) is a plant supposed to have many healthy features. The present study was done to evaluate the anti-anemic effect of beetroot supplement on anemia induced by phenylhydrazine in albino rats. Fifty rats were randomly divided into five equal groups. The control group was kept normal rats. In the second group, anemia was induced in rats by intraperitoneal injection of phenylhydrazine at 60 mg/kg in 3 divided doses daily, for 3 consecutive days. The last three groups received phenylhydrazine as the anemic group. Then, the third group received beetroot extract in dose 200 mg/kg for 24 days. The fourth group received beetroot powder in dose 1000 mg/kg for 24 days. The last group received iron (III) hydroxide polymaltose complex in dose 5mg/kg for 24 days. Our results showed that hemolytic anemia induced by phenylhydrazine in rats caused alteration in the blood picture, iron indices, serum biochemical parameters, antioxidant biomarkers, and histopathological picture. However, the supplementation with beetroot ameliorated these alterations, especially beetroot powder which showed powerful health effects compared to beetroot extract and iron preparation.

Iron deficiency anaemia in pregnancy: A contemporary review

Iron deficiency anaemia is a global health problem, which particularly affects pregnant women. Iron deficiency anaemia during pregnancy is associated with increased maternal and perinatal morbidity and mortality. Maternal iron deficiency may also be associated with neurocognitive deficits in infants. Iron requirements increase during pregnancy and are influenced by hepcidin, the master regulator of iron homeostasis. The enduring global burden of maternal anaemia suggests that currently employed iron supplementation strategies are suboptimal. Recent developments in our understanding of systemic and placental iron homeostasis may improve therapeutic effectiveness by altering the dose and frequency of oral iron. Intravenous iron appears to be a safe treatment to correct maternal anaemia rapidly but research on patient-centred outcomes and cost-effectiveness is needed. Future trials should be adequately powered to assess outcomes relevant to pregnant women.

Maternal haemoglobin in pregnancy and offspring childhood weight and height trajectories: analysis of a prospective birth cohort study

Background: Both anaemia and high haemoglobin in pregnancy are associated with adverse pregnancy outcomes including foetal growth restriction. The objective of this study was to investigate the associations between maternal haemoglobin in pregnancy and trajectories of length/height and weight from birth through childhood. Methods: Data from 7,597 singleton pregnancies in the Avon Longitudinal Study of Parents and Children (ALSPAC), an ongoing, prospective, UK population-based pregnancy cohort study were used. We examined associations between maternal haemoglobin (overall pregnancy and trimester specific) and offspring length and weight at birth, as well as trajectories of height and weight gain from birth to age 10 years derived from multilevel models. Results: Mean pregnancy haemoglobin was 11.61 g/dL (SD 1.12). For each 1g/dL higher mean overall pregnancy haemoglobin, offspring were on average -0.30 cm shorter (95%CI: -0.35, -0.24, p <0.001), and -97.7 g lighter (95%CI: -110.42, -84.93, p <0.001) at birth when adjusting for potential confounders. Trimester specific inverse associations with birth length and weight were strongest for third trimester haemoglobin. There was evidence of a positive association between maternal haemoglobin levels and offspring height gain up to the age of one year and no strong evidence of associations between pregnancy haemoglobin and childhood weight gain. Conclusions: In high income countries, higher maternal haemoglobin in pregnancy may be a concern, as well as anaemia. Further studies are needed to define ‘high’ haemoglobin in pregnancy and whether monitoring of women with high pregnancy haemoglobin is warranted.

The Impact of Nutrition-Specific and Nutrition-Sensitive Interventions on Hemoglobin Concentrations and Anemia: A Meta-review of Systematic Reviews

Anemia is a multifactorial condition arising from inadequate nutrition, infection, chronic disease, and genetic-related etiologies. Our aim was to assess the impact of nutrition-sensitive and nutrition-specific interventions on hemoglobin (Hb) concentrations and anemia to inform the prioritization and scale-up of interventions to address the multiple causes of anemia. We performed a meta-review synthesis of information by searching multiple databases for reviews published between 1990 and 2017 and used standard methods for conducting a meta-review of reviews, including double independent screening, extraction, and quality assessment. Quantitative pooling and narrative syntheses were used to summarize information. Hb concentration and anemia outcomes were pooled in specific population groups (children aged <5 y, school-age children, and pregnant women). Methodological quality of the systematic reviews was assessed using Assessing the Methodological Quality of Systematic Reviews (AMSTAR) criteria. Of the 15,444 records screened, we identified 118 systematic reviews that met inclusion criteria. Reviews focused on nutrition-specific interventions (96%). Daily and intermittent iron supplementation, micronutrient powders, malaria treatment, use of insecticide-treated nets (ITNs), and delayed cord clamping were associated with increased Hb concentration in children aged <5 y. Among children older than 5 y, daily and intermittent iron supplementation and deworming, and in pregnant women, daily iron-folic acid supplementation, use of ITNs, and delayed cord clamping, were associated with increased Hb concentration. Similar results were obtained for the reduced risk of anemia outcome. This meta-review suggests the importance of nutrition-specific interventions for anemia and highlights the lack of evidence to understand the influence of nutrition-sensitive and multifaceted interventions on the condition.

Differences in the frequency of genetic variants associated with iron imbalance among global populations

Iron deficiency anaemia is a major health problem affecting approximately 1.2 billion people worldwide. Young children, women of reproductive age and pregnant women living in sub-Saharan Africa are the most vulnerable. It is estimated that iron deficiency accounts for half of anaemia cases. Apart from nutritional deficiency, infection, inflammation and genetic factors are the major drivers of anaemia. However, the role of genetic risk factors has not been thoroughly investigated. This is particularly relevant in African populations, as they carry high genetic diversity and have a high prevalence of anaemia. Multiple genetic variations in iron regulatory genes have been linked to impaired iron status. Here we conducted a literature review to identify genetic variants associated with iron imbalance among global populations. We compare their allele frequencies and risk scores and we investigated population-specific selection among populations of varying geographic origin using data from the Keneba Biobank representing individuals in rural Gambia and the 1000 Genomes Project. We identified a significant lack of data on the genetic determinants of iron status in sub-Saharan Africa. Most of the studies on genetic determinants of iron status have been conducted in Europeans. Also, we identified population differences in allele frequencies in candidate putative genetic risk factors. Given the disproportionately high genetic diversity in African populations coupled with their high prevalence of iron deficiency, there is need to investigate the genetic influences of low iron status in Sub-Saharan Africa. The resulting insights may inform the future implementation of iron intervention strategies.

The role of iron repletion in adult iron deficiency anemia and other diseases

Iron deficiency anemia (IDA) is the most prevalent and treatable form of anemia worldwide. The clinical management of patients with IDA requires a comprehensive understanding of the many etiologies that can lead to iron deficiency including pregnancy, blood loss, renal disease, heavy menstrual bleeding, inflammatory bowel disease, bariatric surgery, or extremely rare genetic disorders. The treatment landscape for many causes of IDA is currently shifting toward more abundant use of intravenous (IV) iron due to its effectiveness and improved formulations that decrease the likelihood of adverse effects. IV iron has found applications beyond treatment of IDA, and there is accruing data about its efficacy in patients with heart failure, restless leg syndrome, fatigue, and prevention of acute mountain sickness. This review provides a framework to diagnose, manage, and treat patients presenting with IDA and discusses other conditions that benefit from iron supplementation.

Maternal iron intake during pregnancy and the risk of small for gestational age

Studies of iron and its association with the risk of small for gestational age (SGA) show inconsistent results. Consuming iron supplements during pregnancy is controversial because of possible risks. This study assessed the association between iron intake and the risk of having an SGA newborn and whether iron intake is associated with gestational diabetes. A case-control study of 518 pairs of Spanish women who were pregnant and attending five hospitals was conducted. Groups were matched 1:1 for age (±2 years) and hospital. Cases were women with an SGA newborn at delivery. Controls were women with normal-sized newborns at delivery. Data were gathered on demographic characteristics, socio-economic status, adverse habits (like smoking), and diet. A 137-item food frequency questionnaire was completed. Iron intakes were categorized in quintiles (Q1-Q5). Crude odds ratios (ORs) and adjusted ORs (aORs) with 95% confidence intervals (CIs) were estimated by conditional logistic regression. No significant relationship was found between dietary iron intake and SGA. A protective association was found for women receiving iron supplementation >40 mg/day and SGA versus women not taking supplements (aOR = 0.64, 95% CI [0.42, 0.99]). This association was identified in mothers both with (aOR = 0.57, 95% CI [0.40, 0.81]) and without (aOR = 0.64, 95% CI [0.64, 0.97]) anaemia. In women in the control group without anaemia, iron supplementation >40 mg/day was positively associated with gestational diabetes (aOR = 6.32, 95% CI [1.97, 20.23]). Iron supplementation in pregnancy may prevent SGA independently of existing anaemia but may also increase the risk of gestational diabetes.

Maternal anemia and birth weight: A prospective cohort study

OBJECTIVE

To investigate the association between maternal anemia and low/insufficient birth weight.

DESIGN

A prospective cohort study of pregnant women who underwent prenatal care at the healthcare units in a municipality of northeast Brazil together with their newborn infants was carried out. The pregnant women were classified as having anemia when the hemoglobin level was below 11 g/dl. Infants who were born full term weighing less than 2500 grams were classified as low birth weight, and those weighing between 2500 and 2999 grams were classified as insufficient weight. The occurrence of maternal anemia and its association with birth weight was verified using crude and adjusted Relative Risk (RR) estimates with their corresponding 95% confidence intervals (95%CIs).

RESULTS

The final sample was comprised of 622 women. Maternal anemia was considered a risk factor for low/insufficient birth weight, after adjusting the effect measurement for maternal age, family income, urinary infection, parity, alcoholic beverage consumption during pregnancy and gestational body mass index: RRadjusted = 1.38 [95% CI: 1.07 to 1.77].

CONCLUSIONS

Maternal anemia was associated with low/insufficient birth weight, representing a risk factor for the gestational outcomes studied.

Strategies to reduce non-communicable diseases in the offspring: negative and positive in utero programming

Non-communicable diseases (NCDs) are a major problem as they are the leading cause of death and represent a substantial economic cost. The 'Developmental Origins of Health and Disease Hypothesis' proposes that adverse stimuli at different life stages can increase the predisposition to these diseases. In fact, adverse in utero programming is a major origin of these diseases due to the high malleability of embryonic development. This review provides a comprehensive analysis of the scientific literature on in utero programming and NCDs highlighting potential medical strategies to prevent these diseases based upon this programming. We fully address the concept and mechanisms involved in this programming (anatomical disruptions, epigenetic modifications and microbiota alterations). We also examine the negative role of in utero programming on the increased predisposition of NCDs in the offspring, which introduces the passive medical approach that consists of avoiding adverse stimuli including an unhealthy diet and environmental chemicals. Finally, we extensively discuss active medical approaches that target the causes of NCDs and have the potential to significantly and rapidly reduce the incidence of NCDs. These approaches can be classified as direct in utero programming modifications and personalized lifestyle pregnancy programs; they could potentially provide transgenerational NCDs protection. Active strategies against NCDs constitute a promising tool for the reduction in NCDs.

Can Gestational Anemia be Alleviated with Increased Awareness of its Causes and Management Strategies? Implications for Health Care Services

Objectives

We conducted this study to assess the risk factors of gestational anemia and evaluate the effectiveness of a culturally-tailored nutrition educational intervention on hemoglobin (Hb) status among pregnant Omani women. Newborn birthweight was used as a birth outcome.

Methods

The study was conducted in two phases. The first phase investigated the risk factors associated with gestational anemia in 206 Omani women who were ³ 20 years old and had at least completed 12 weeks of gestation. A suitable sample was recruited at a tertiary teaching hospital in Muscat, Oman. Hb status was recorded, and backward linear regression was used to analyze the demographic and obstetric variables associated with Hb levels. In the second phase, a specially designed culturally-tailored nutrition educational intervention was delivered to women in the study group by trained research assistants whereas women in the control group received routine care only. The Hb levels of the pregnant women and birth weight of newborns after the intervention were evaluated in the second phase of the study.

Results

The prevalence of gestational anemia among 206 pregnant Omani women was 41.7%. A significant negative relationship was found between Hb and parity whereas a positive relationship was found between Hb and gestational age. The Hb level increased as the gestational age advanced (β = 0.31, p < 0.050) and decreased as the parity increased (β = -0.22, p < 0.050). The pre-post mean difference of Hb levels in the study group was 11.0 g/dL and in the control group was 10.7 g/dL. The difference between the pre- and post-test Hb levels for the study group was significant (t = 3.58, p = 0.001), indicating that the culturally-tailored nutrition education intervention was effective in improving the Hb level in pregnant Omani women. No significant difference was found between the study and control group with respect to birth outcomes.

Conclusion

The prevalence of gestational anemia is high in pregnant Omani women. The use of a specially designed culturally-tailored nutrition education intervention for pregnant women supplemented with follow-up reminders can reduce the occurrence of gestational anemia. Such programs are ultimately necessary in light of the high prevalence of gestational anemia in developing countries.

Management of Iron Deficiency Anemia in Pregnancy in India

Iron deficiency anemia (IDA) continues to be the commonest etiology of anemia in pregnancy. The prevalence of iron deficiency (ID) in pregnant Indian women is amongst the highest in the world. Untreated iron deficiency (ID) has significant adverse feto-maternal consequences. Plethora of investigations are available for diagnosis of IDA, each having specific advantages and disadvantages when used in the pregnancy setting. Therapy for ID includes dietary modification, oral iron supplementation, intravenous iron and blood transfusion. Newer parenteral iron preparations are safe and there is mounting evidence to suggest their use in frontline settings for pregnancy associated IDA in the second and third trimester. Through this review, we suggest an algorithm for diagnosis and treatment of IDA in pregnancy depending on the severity of anemia and period of gestation suited for widespread use in resource limited settings. Also, we recommend ways for increasing public awareness and tackling this health issue including the observance of "National Anemia Awareness and Treatment Day."

Dietary strategies for improving iron status: balancing safety and efficacy

In light of evidence that high-dose iron supplements lead to a range of adverse events in low-income settings, the safety and efficacy of lower doses of iron provided through biological or industrial fortification of foodstuffs is reviewed. First, strategies for point-of-manufacture chemical fortification are compared with biofortification achieved through plant breeding. Recent insights into the mechanisms of human iron absorption and regulation, the mechanisms by which iron can promote malaria and bacterial infections, and the role of iron in modifying the gut microbiota are summarized. There is strong evidence that supplemental iron given in nonphysiological amounts can increase the risk of bacterial and protozoal infections (especially malaria), but the use of lower quantities of iron provided within a food matrix, ie, fortified food, should be safer in most cases and represents a more logical strategy for a sustained reduction of the risk of deficiency by providing the best balance of risk and benefits. Further research into iron compounds that would minimize the availability of unabsorbed iron to the gut microbiota is warranted.

Perspectives on the design and methodology of periconceptional nutrient supplementation trials

Periconceptional supplementation could extend the period over which maternal and fetal nutrition is improved, but there are many challenges facing early-life intervention studies. Periconceptional trials differ from pregnancy supplementation trials, not only because of the very early or pre-gestational timing of nutrient exposure but also because they generate subsidiary information on participants who remain non-pregnant. The methodological challenges are more complex although, if well designed, they provide opportunities to evaluate concurrent hypotheses related to the health of non-pregnant women, especially nulliparous adolescents. This review examines the framework of published and ongoing randomised trial designs. Four cohorts typically arise from the periconceptional trial design--two of which are non-pregnant and two are pregnant--and this structure provides assessment options related to pre-pregnant, maternal, pregnancy and fetal outcomes. Conceptually the initial decision for single or micronutrient intervention is central--as is the choice of dosage and content--in order to establish a comparative framework across trials, improve standardisation, and facilitate interpretation of mechanistic hypotheses. Other trial features considered in the review include: measurement options for baseline and outcome assessments; adherence to long-term supplementation; sample size considerations in relation to duration of nutrient supplementation; cohort size for non-pregnant and pregnant cohorts as the latter is influenced by parity selection; integrating qualitative studies and data management issues. Emphasis is given to low resource settings where high infection rates and the possibility of nutrient-infection interactions may require appropriate safety monitoring. The focus is on pragmatic issues that may help investigators planning a periconceptional trial.

Lipid-based nutrient supplements for pregnant women reduce newborn stunting in a cluster-randomized controlled effectiveness trial in Bangladesh

BACKGROUND

Maternal undernutrition and newborn stunting [birth length-for-age z score (LAZ) <-2] are common in Bangladesh.

OBJECTIVE

The objective was to evaluate the effect of lipid-based nutrient supplements for pregnant and lactating women (LNS-PLs) on birth outcomes.

DESIGN

We conducted a cluster-randomized effectiveness trial (the Rang-Din Nutrition Study) within a community health program in rural Bangladesh. We enrolled 4011 pregnant women at ≤20 gestational weeks; 48 clusters received iron and folic acid (IFA; 60 mg Fe + 400 μg folic acid) and 16 clusters received LNS-PLs (20 g/d, 118 kcal) containing essential fatty acids and 22 vitamins and minerals. Both of the supplements were intended for daily consumption until delivery. Primary outcomes were birth weight and length.

RESULTS

Infants in the LNS-PL group had higher birth weights (2629 ± 408 compared with 2588 ± 413 g; P = 0.007), weight-for-age z scores (-1.48 ± 1.01 compared with -1.59 ± 1.02; P = 0.006), head-circumference-for-age z scores (HCZs; -1.26 ± 1.08 compared with -1.34 ± 1.12; P = 0.028), and body mass index z scores (-1.57 ± 1.05 compared with -1.66 ± 1.03; P = 0.005) than those in the IFA group; in adjusted models, the differences in length (47.6 ± 0.07 compared with 47.4 ± 0.04 cm; P = 0.043) and LAZ (-1.15 ± 0.04 compared with -1.24 ± 0.02; P = 0.035) were also significant. LNS-PLs reduced the risk of newborn stunting (18.7% compared with 22.6%; RR: 0.83; 95% CI: 0.71, 0.97) and small head size (HCZ <-2) (20.7% compared with 24.9%; RR: 0.85; 95% CI: 0.73, 0.98). The effects of LNS-PL on newborn stunting were greatest in infants born before a 10-wk interruption in LNS-PL distribution (n = 1301; 15.7% compared with 23.6%; adjusted RR: 0.69; 95% CI: 0.53, 0.89) and in infants born to women ≤24 y of age or with household food insecurity.

CONCLUSION

Prenatal lipid-based nutrient supplements can improve birth outcomes in Bangladeshi women, especially those at higher risk of fetal growth restriction. This trial was registered at clinicaltrials.gov as NCT01715038.

"There is iron and iron…" Burkinabè women's perceptions of iron supplementation: a qualitative study

Most pregnant women in Burkina Faso are iron deficient and many are anemic. This study assessed women's understanding of anemia and the role of iron in preventing and treating this condition. A qualitative study was conducted within a randomized controlled trial of weekly iron supplementation in a rural malaria endemic area. Focus groups with women of similar age, parity, and marital status took place in 12 of 24 study villages. Two additional focus groups were conducted with female field workers. Tape-recorded transcripts were translated into French and analyzed using Framework analysis. Anemia, for which no Mooré term or traditional treatment for anemia was evident, was described in terms of blood volume. Moderate blood loss (diminished blood) could be easily replaced by eating well and was not considered serious. Massive blood loss (finished blood) was a rare, life-threatening illness. Iron tablets could increase blood volume and help women withstand massive blood loss at delivery, but for the latter, transfusion was indicated. Women had no knowledge of iron's role and did not readily concede that iron supplements contained elemental iron. Neither adolescents nor field workers were convinced of the benefits of supplementing non-pregnant adolescents, who were incorrectly considered to be at low risk of anemia. Young women's knowledge of anemia did not provide an adequate explanatory framework to motivate anemia prevention. Improving information on the role of iron is especially important for adolescent girls who may be incorrectly considered at low risk of anemia as they have not yet experienced pregnancy.

Intermittent oral iron supplementation during pregnancy

BACKGROUND

Anaemia is a frequent condition during pregnancy, particularly among women in low- and middle-income countries. Traditionally, gestational anaemia has been prevented with daily iron supplements throughout pregnancy, but adherence to this regimen due to side effects, interrupted supply of the supplements, and concerns about safety among women with an adequate iron intake, have limited the use of this intervention. Intermittent (i.e. two or three times a week on non-consecutive days) supplementation has been proposed as an alternative to daily supplementation.

OBJECTIVES

To assess the benefits and harms of intermittent supplementation with iron alone or in combination with folic acid or other vitamins and minerals to pregnant women on neonatal and pregnancy outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2015), the WHO International Clinical Trials Registry Platform (ICTRP) (31 July 2015) and contacted relevant organisations for the identification of ongoing and unpublished studies (31 July 2015).

SELECTION CRITERIA

Randomised or quasi-randomised trials.

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.

MAIN RESULTS

This review includes 27 trials from 15 countries, but only 21 trials (with 5490 women) contributed data to the review. All studies compared daily versus intermittent iron supplementation. The methodological quality of included studies was mixed and most had high levels of attrition.The overall assessment of the quality of the evidence for primary infant outcomes was low and for maternal outcomes very low.Of the 21 trials contributing data, three studies provided intermittent iron alone, 14 intermittent iron + folic acid and four intermittent iron plus multiple vitamins and minerals in comparison with the same composition of supplements provided in a daily regimen.Overall, for women receiving any intermittent iron regimen (with or without other vitamins and minerals) compared with a daily regimen there was no clear evidence of differences between groups for any infant primary outcomes: low birthweight (average risk ratio (RR) 0.82; 95% confidence interval (CI) 0.55 to 1.22; participants = 1898; studies = eight; low quality evidence), infant birthweight (mean difference (MD) 5.13 g; 95% CI -29.46 to 39.72; participants = 1939; studies = nine; low quality evidence), premature birth (average RR 1.03; 95% CI 0.76 to 1.39; participants = 1177; studies = five; low quality evidence), or neonatal death (average RR 0.49; 95% CI 0.04 to 5.42; participants = 795; studies = one; very low quality). None of the studies reported congenital anomalies.For maternal outcomes, there was no clear evidence of differences between groups for anaemia at term (average RR 1.22; 95% CI 0.84 to 1.80; participants = 676; studies = four; I² = 10%; very low quality). Women receiving intermittent supplementation had fewer side effects (average RR 0.56; 95% CI 0.37 to 0.84; participants = 1777; studies = 11; I² = 87%; very low quality) and were at lower risk of having high haemoglobin (Hb) concentrations (greater than 130 g/L) during the second or third trimester of pregnancy (average RR 0.53; 95% CI 0.38 to 0.74; participants = 2616; studies = 15; I² = 52%; (this was not a primary outcome)) compared with women receiving daily supplements. There were no significant differences in iron-deficiency anaemia at term between women receiving intermittent or daily iron + folic acid supplementation (average RR 0.71; 95% CI 0.08 to 6.63; participants = 156; studies = one). There were no maternal deaths (six studies) or women with severe anaemia in pregnancy (six studies). None of the studies reported on iron deficiency at term or infections during pregnancy.Most of the studies included in the review (14/21 contributing data) compared intermittent oral iron + folic acid supplementation compared with daily oral iron + folic acid supplementation (4653 women) and findings for this comparison broadly reflect findings for the main comparison (any intermittent versus any daily regimen).Three studies with 464 women examined supplementation with intermittent oral iron alone compared with daily oral iron alone. There were no clear differences between groups for mean birthweight, preterm birth, maternal anaemia or maternal side effects. Other primary outcomes were not reported.Four studies with a combined sample size of 412 women compared intermittent oral iron + vitamins and minerals supplementation with daily oral iron + vitamins and minerals supplementation. Results were not reported for any of the review's infant primary outcomes. One study reported fewer maternal side effects in the intermittent iron group, and two studies that more women were anaemic at term compared with those receiving daily supplementation.Where sufficient data were available for primary outcomes, we set up subgroups to look for possible differences between studies in terms of earlier or later supplementation; women's anaemia status at the start of supplementation; higher and lower weekly doses of iron; and the malarial status of the region in which the trials were conducted. There was no clear effect of these variables on results.

AUTHORS' CONCLUSIONS

This review is the most comprehensive summary of the evidence assessing the benefits and harms of intermittent iron supplementation in pregnant women on haematological and pregnancy outcomes. Findings suggest that intermittent regimens produced similar maternal and infant outcomes as daily supplementation but were associated with fewer side effects and reduced the risk of high levels of Hb in mid and late pregnancy, although the risk of mild anaemia near term was increased. While the quality of the evidence was assessed as low or very low, intermittent may be a feasible alternative to daily iron supplementation among those pregnant women who are not anaemic and have adequate antenatal care.

Vitamin C supplementation in pregnancy

BACKGROUND

Vitamin C supplementation may help reduce the risk of pregnancy complications such as 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 METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 March 2015) and reference lists of retrieved studies.

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 review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy.

MAIN RESULTS

Twenty-nine trials involving 24,300 women are included in this review. Overall, 11 trials were judged to be of low risk of bias, eight were high risk of bias and for 10 trials it was unclear. No clear differences were seen between women supplemented with vitamin C alone or in combination with other supplements compared with placebo or no control for the risk of stillbirth (risk ratio (RR) 1.15, 95% confidence intervals (CI) 0.89 to 1.49; 20,038 participants; 11 studies; I² = 0%; moderate quality evidence), neonatal death (RR 0.79, 95% CI 0.58 to 1.08; 19,575 participants; 11 studies; I² = 0%), perinatal death (average RR 1.07, 95% CI 0.77 to 1.49; 17,105 participants; seven studies; I² = 35%), birthweight (mean difference (MD) 26.88 g, 95% CI -18.81 to 72.58; 17,326 participants; 13 studies; I² = 69%), intrauterine growth restriction (RR 0.98, 95% CI 0.91 to 1.06; 20,361 participants; 12 studies; I² = 15%; high quality evidence), preterm birth (average RR 0.99, 95% CI 0.90 to 1.10; 22,250 participants; 16 studies; I² = 49%; high quality evidence), preterm PROM (prelabour rupture of membranes) (average RR 0.98, 95% CI 0.70 to 1.36; 16,825 participants; 10 studies; I² = 70%; low quality evidence), term PROM (average RR 1.26, 95% CI 0.62 to 2.56; 2674 participants; three studies; I² = 87%), and clinical pre-eclampsia (average RR 0.92, 95% CI 0.80 to 1.05; 21,956 participants; 16 studies; I² = 41%; high quality evidence).Women supplemented with vitamin C alone or in combination with other supplements compared with placebo or no control were at decreased risk of having a placental abruption (RR 0.64, 95% CI 0.44 to 0.92; 15,755 participants; eight studies; I² = 0%; high quality evidence) and had a small increase in gestational age at birth (MD 0.31, 95% CI 0.01 to 0.61; 14,062 participants; nine studies; I² = 65%), however they were also more likely to self-report abdominal pain (RR 1.66, 95% CI 1.16 to 2.37; 1877 participants; one study). In the subgroup analyses based on the type of supplement, vitamin C supplementation alone was associated with a reduced risk of preterm PROM (average RR 0.66, 95% CI 0.48 to 0.91; 1282 participants; five studies; I² = 0%) and term PROM (average RR 0.55, 95% CI 0.32 to 0.94; 170 participants; one study). Conversely, the risk of term PROM was increased when supplementation included vitamin C and vitamin E (average RR 1.73, 95% CI 1.34 to 2.23; 3060 participants; two studies; I² = 0%). There were no differences in the effects of vitamin C on other outcomes in the subgroup analyses examining the type of supplement. There were no differing patterns in other subgroups of women based on underlying risk of pregnancy complications, timing of commencement of supplementation or dietary intake of vitamin C prior to trial entry. The GRADE quality of the evidence was high for intrauterine growth restriction, preterm birth, and placental abruption, moderate for stillbirth and clinical pre-eclampsia, low for preterm PROM.

AUTHORS' CONCLUSIONS

The data do not support routine vitamin C supplementation alone or in combination with other supplements for the prevention of fetal or neonatal death, poor fetal growth, preterm birth or pre-eclampsia. Further research is required to elucidate the possible role of vitamin C in the prevention of placental abruption and prelabour rupture of membranes. There was no convincing evidence that vitamin C supplementation alone or in combination with other supplements results in other important benefits or harms.

Extrinsic tooth staining potential of high dose and sustained release iron syrups on primary teeth

Background

Iron in the form of oral supplements is routinely prescribed to children to help fight anemia, however tooth staining is a commonly reported complication. This study tests in vitro, the staining potential of two different forms of iron syrup on primary teeth.

Methods

Forty caries free primary central incisors were divided into four groups of ten teeth each. The control group comprised of ten teeth immersed in artificial saliva, while the test solutions were comprised of different forms of iron mixed with vitamins such that the iron content of each solution was approximately 100 mg (from 100 to 101.1 mg). The test solutions used iron syrup (Ferrose®, SPIMACO, Jeddah, Saudi Arabia) with iron in the form of ferric oxide polymaltose (FOP), slow release formula (Ferroglobin®, Vitabiotics ltd., London, UK) containing ferrous fumarate (FF and a combination of the two (FOP + FF). All the teeth were then immersed for 72 h and subjected to a protocol developed by Lee et al. to test staining. Color changes were measured using a wave dispersion spectro-photometer (Color-Eye 7000A, X-Rite Gmbh, Regensdorf, Switzerland) on the exposed labial surface at 4, 8, 24, 48 and 72 h. Two-way ANOVA with Scheffe’s post hoc test was used to determine significance of difference in shade, while the Kurskull-Wallis test used to determine the significance of difference in clinical staining (∆E > 3).

Results

While all three iron groups showed some amount of staining, the combination of the two forms of iron (FOP+FF) showed significantly lower incidence of clinical staining than the other two groups at the end of 72 h. At the end of 72 h the (FOP) had significantly higher ∆E than ferrrous fumarate (FF ) while the combination (FOP+ FF) had a significantly lower ∆E than either group.

Conclusion

In an in vitro model, combining different forms of iron seems to elicit a lower intensity of staining than equivalent doses of a single form of iron.

Electronic supplementary material

The online version of this article (doi:10.1186/s12903-015-0072-0) contains supplementary material, which is available to authorized users.

Daily oral iron supplementation during pregnancy

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.

Multiple micronutrient powders for home (point-of-use) fortification of foods in pregnant women

BACKGROUND

It is estimated that 32 million pregnant women suffer from anaemia worldwide. Due to increased metabolic demands, pregnant women are particularly vulnerable to anaemia and vitamin and mineral deficiencies, leading to adverse health effects in both the mother and her baby. Despite the demonstrated benefits of prenatal supplementation with iron and folic acid or multiple micronutrients, poor adherence to routine supplementation has limited the effectiveness of this intervention in many settings. Micronutrient powders for point-of-use fortification are packed, single-dose sachets containing vitamins and minerals that can be added onto prepared food to improve its nutrient profile. The use of multiple micronutrient powders for point-of-use fortification of foods in pregnant women could be an alternative intervention to prenatal micronutrient supplementation.

OBJECTIVES

To assess the effects of prenatal home (point-of-use) fortification of foods with multiple micronutrient powders on maternal and newborn health.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2015) and the International Clinical Trials Registry Platform (ICTRP) (31 January 2015). We also contacted relevant agencies to identify ongoing and unpublished studies.

SELECTION CRITERIA

Randomised controlled trials (both individual and cluster randomisation) and quasi-randomised trials, irrespective of language or publication status.The intervention was micronutrient powders for point-of-use fortification of foods, containing at least three micronutrients with one of them being iron, provided to pregnant women of any gestational age and parity. Five comparison groups were considered: no intervention/placebo, iron and folic acid supplements, iron-only supplements, folic-acid only supplements, and multiple micronutrients in supplements.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of studies, extracted and checked data accuracy, and assessed the risk of bias of included studies.

MAIN RESULTS

Our search identified 12 reports (relating to six studies). We included two cluster-randomised controlled trials (involving 1172 women) - these trials were considered to be at a moderate to high risk of bias due to methodological limitations. One trial is ongoing, and three studies were excluded. Micronutrient powders for point-of-use fortification of foods versus iron and folic acid supplementsOne trial (involving 478 pregnant women attending 42 antenatal care centres) compared micronutrient powders containing iron, folic acid, vitamin C and zinc with iron and folic acid tablets provided daily from 14 to 22 weeks to 32 weeks' gestation. The trial did not report on any of this review's primary outcomes: maternal anaemia at or near term, maternal iron deficiency, maternal mortality, adverse effects, low birthweight, preterm births. Nor did the trial report on the majority of this review's secondary outcomes, with the exception of maternal adherence. Adherence to micronutrient powders was lower than adherence to iron and folic acid supplements (risk ratio (RR) 0.76, 95% confidence interval (CI) 0.66 to 0.87, one study, n = 405). Micronutrient powders for point-of-use fortification of foods versus same multiple micronutrients in supplementsOne study (involving 694 pregnant women from 18 communities), compared micronutrient powders containing iron, folic acid, vitamin C, zinc, iodine, vitamin E and vitamin B12 with tablets containing the same seven micronutrients. There was no difference in maternal anaemia at 37 weeks of gestation (RR 0.92, 95% CI 0.53 to 1.59, one study, n = 470, very low quality evidence). The trial did not report on any of this review's other primary outcomes in relation to maternal iron deficiency, maternal mortality, adverse effects, low birthweight, or preterm birth. In terms of this review's secondary outcomes, the included trial did not report on the majority of this review's prespecified secondary outcomes with one exception - there was no clear difference in maternal haemoglobin Hb or near term (mean difference (MD) 1.0 g/L, 95% CI -1.77 to 3.77, one study, n = 470).

AUTHORS' CONCLUSIONS

Limited evidence suggests that micronutrient powders for point-of-use fortification of foods have no clear difference as multiple micronutrient supplements on maternal anaemia (very low quality evidence) and Hb at or near term. There is limited evidence to suggest that women were more likely to adhere to taking tablets than using micronutrient powders.The overall quality of evidence was judged very low (due to methodological limitations), and no evidence was available for the majority of primary and secondary outcomes. Therefore, more evidence is needed to assess the potential benefits or harms of the use of micronutrient powders in pregnant women on maternal and infant health outcomes. Future trials should also assess adherence to micronutrient powders and be adequately powered to evaluate the effects on birth outcomes and morbidity.

A prospective observational description of frequency and timing of antenatal care attendance and coverage of selected interventions from sites in Argentina, Guatemala, India, Kenya, Pakistan and Zambia

Background

The Global Network for Women’s and Children’s Health Research is one of the largest international networks for testing and generating evidence-based recommendations for improvement of maternal-child health in resource-limited settings. Since 2009, Global Network sites in six low and middle-income countries have collected information on antenatal care practices, which are important as indicators of care and have implications for programs to improve maternal and child health. We sought to: (1) describe the quantity of antenatal care attendance over a four-year period; and (2) explore the quality of coverage for selected preventative, screening, and birth preparedness components.

Methods

The Maternal Newborn Health Registry (MNHR) is a prospective, population-based birth and pregnancy outcomes registry in Global Network sites, including: Argentina, Guatemala, India (Belgaum and Nagpur), Kenya, Pakistan, and Zambia. MNHR data from these sites were prospectively collected from January 1, 2010 – December 31, 2013 and analyzed for indicators related to quantity and patterns of ANC and coverage of key elements of recommended focused antenatal care. Descriptive statistics were generated overall by global region (Africa, Asia, and Latin America), and for each individual site.

Results

Overall, 96% of women reported at least one antenatal care visit. Indian sites demonstrated the highest percentage of women who initiated antenatal care during the first trimester. Women from the Latin American and Indian sites reported the highest number of at least 4 visits. Overall, 88% of women received tetanus toxoid. Only about half of all women reported having been screened for syphilis (49%) or anemia (50%). Rates of HIV testing were above 95% in the Argentina, African, and Indian sites. The Pakistan site demonstrated relatively high rates for birth preparation, but for most other preventative and screening interventions, posted lower coverage rates as compared to other Global Network sites.

Conclusions

Results from our large, prospective, population-based observational study contribute important insight into regional and site-specific patterns for antenatal care access and coverage. Our findings indicate a quality and coverage gap in antenatal care services, particularly in regards to syphilis and hemoglobin screening. We have identified site-specific gaps in access to, and delivery of, antenatal care services that can be targeted for improvement in future research and implementation efforts.

Trial registration

Registration at Clinicaltrials.gov (ID# NCT01073475)

Antenatal Iron Supplementation Regimens for Pregnant Women in Rural Vietnam and Subsequent Haemoglobin Concentration and Anaemia among Their Infants

BACKGROUND

Little evidence about the effects of antenatal iron supplementation on infant anaemia is available. The aim was to compare effects on six-month-old infants' Haemoglobin (Hb) concentration and anaemia of daily iron-folic acid (IFA), twice-weekly IFA with or without other micronutrients (MMN) and usual antenatal care in rural Vietnam.

METHODS AND FINDINGS

Secondary data analysis from: a prospective population-based observational study (OS) which examined effects of antenatal psychosocial factors, anaemia and iron deficiency on infant development and health; and a three-arm cluster randomised trial (CRT) of different antenatal iron supplementation regimens. In the OS 497 women (<20 weeks gestation) from 50 randomly-selected communes participated, and in the CRT 1,258 pregnant women (<16 weeks gestation) in 104 communes were allocated randomly to trial arms. The main outcome was six-month-old infant Hb concentration. Baseline data included women's socio-demographic characteristics, reproductive health, Hb and serum ferritin. Mean differences in infant Hb and odds ratios of infant anaemia between CRT arms and OS were calculated by multivariable regression models, controlling for baseline differences and clustering, using robust standard errors. Infant anaemia prevalence was 68.6% in the OS, 47.2% daily IFA, 53.5% weekly IFA, and 50.3% MMN conditions. After adjustment, mean infant haemoglobin levels in daily IFA (mean difference = 0.95 g/dL; 95%CI 0.7-11.18); weekly IFA (0.91; 95%CI 0.69-1.12) and MMN (1.04; 95%CI 0.8-1.27) were higher than in the OS. After adjustment there were lower odds ratios of anaemia among infants in the daily IFA (OR = 0.31; 95% CI 0.22-0.43), weekly IFA (0.38; 95%CI 0.26-0.54) and MMN (0.33; 95%CI 0.23-0.48) groups than in the OS.

CONCLUSIONS

Infant anaemia is a public health problem in Vietnam and other resource-constrained countries. All supplementation regimens could have clinically significant benefits for Hb and reduce anaemia risk among six-month-old infants. Universal provision of free intermittent iron supplements is warranted.

Routine iron supplementation and screening for iron deficiency anemia in pregnancy: a systematic review for the U.S. Preventive Services Task Force

BACKGROUND

Routine screening and supplementation for iron deficiency anemia (IDA) in asymptomatic, nonanemic pregnant women could improve maternal and infant health outcomes.

PURPOSE

Update of a 2006 systematic review by the U.S. Preventive Services Task Force on screening and supplementation for IDA in pregnancy.

DATA SOURCES

MEDLINE and the Cochrane Library (1996 to August 2014) and reference lists of relevant systematic reviews to identify studies published since 1996.

STUDY SELECTION

English-language trials and controlled observational studies about effectiveness of screening and routine supplementation for IDA in developed countries.

DATA EXTRACTION

Data extraction and quality assessment confirmed and dual-rated by a second investigator using prespecified criteria.

DATA SYNTHESIS

No study directly compared clinical outcomes or harms of screening or not screening pregnant women for IDA. Twelve supplementation trials were included, and no controlled observational studies met inclusion criteria. On the basis of 11 trials, routine maternal iron supplementation had inconsistent effects on rates of cesarean delivery, small size for gestational age, and low birthweight and no effect on maternal quality of life, gestational age, Apgar scores, preterm birth, or infant mortality. Twelve trials reported improvements in maternal hematologic indices, although not all were statistically significant. Pooled analysis of 4 trials resulted in a statistically significant difference in IDA incidence at term, favoring supplementation (risk ratio, 0.29 [95% CI, 0.17 to 0.49]; I2 = 0%). Maternal iron supplementation did not affect infant iron status at 6 months. Harms, none of which were serious or had long-term consequences, were inconsistently reported in 10 of the trials, with most finding no difference between groups.

LIMITATIONS

Data from trials in countries with limited generalizability to U.S. populations were included. Studies were methodologically heterogeneous, and some were small and underpowered.

CONCLUSION

There is inconclusive evidence that routine prenatal supplementation for IDA improves maternal or infant clinical health outcomes, but supplementation may improve maternal hematologic indices.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.

How can formative research inform the design of an iron-folic acid supplementation intervention starting in first trimester of pregnancy in Bangladesh?

Background

The study objective was to understand community preparedness for iron and folic acid (IFA) supplementation early in pregnancy and to inform the design of a large-scale trial of early introduction of IFA supplementation in rural Bangladesh.

Methods

66 in-depth interviews (pregnant women, husbands, and older women in the household), 20 key-informant interviews, 3 focus-group discussions (community health workers and adolescent female students), and observation of two community-based clinics were conducted.

Results

Most of the women who used IFA tablets during pregnancy reported better health and physical strength after taking them. Women perceived that IFA increased blood volume, leading to foetal nourishment and compensated for blood loss during delivery. However, a culturally informed perceived barrier was the belief that IFA supplementation will increase foetus size, leading to birth complications, hospitalisation, caesarean section and financial burden for the family. Community health workers (CHWs) of BRAC (a non-government organisation) were the main sources of IFA information and supplements, although knowledge of IFA tablets among women’s social networks also helped to make it acceptable. Pregnant women felt that they could start taking IFA during the first trimester of pregnancy if advised by the CHWs. Programme managers and healthcare providers expressed concern about starting IFA supplementation early.

Conclusion

Our study suggests that introduction of IFA supplementation early in pregnancy is feasible with support from CHWs. Promotion of IFA could benefit from efforts to include culturally sensitive reasons for usage; improvement of the CHW training modules; targeted home visits and counselling; and outreach to standardize messages.

Ferrous sulfate supplementation causes significant gastrointestinal side-effects in adults: a systematic review and meta-analysis

Background

The tolerability of oral iron supplementation for the treatment of iron deficiency anemia is disputed.

Objective

Our aim was to quantify the odds of GI side-effects in adults related to current gold standard oral iron therapy, namely ferrous sulfate.

Methods

Systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating GI side-effects that included ferrous sulfate and a comparator that was either placebo or intravenous (IV) iron. Random effects meta-analysis modelling was undertaken and study heterogeneity was summarised using I² statistics.

Results

Forty three trials comprising 6831 adult participants were included. Twenty trials (n = 3168) had a placebo arm and twenty three trials (n = 3663) had an active comparator arm of IV iron. Ferrous sulfate supplementation significantly increased risk of GI side-effects versus placebo with an odds ratio (OR) of 2.32 [95% CI 1.74–3.08, p<0.0001, I² = 53.6%] and versus IV iron with an OR of 3.05 [95% CI 2.07-4.48, p<0.0001, I² = 41.6%]. Subgroup analysis in IBD patients showed a similar effect versus IV iron (OR = 3.14, 95% CI 1.34-7.36, p = 0.008, I² = 0%). Likewise, subgroup analysis of pooled data from 7 RCTs in pregnant women (n = 1028) showed a statistically significant increased risk of GI side-effects for ferrous sulfate although there was marked heterogeneity in the data (OR = 3.33, 95% CI 1.19-9.28, p = 0.02, I² = 66.1%). Meta-regression did not provide significant evidence of an association between the study OR and the iron dose.

Conclusions

Our meta-analysis confirms that ferrous sulfate is associated with a significant increase in gastrointestinal-specific side-effects but does not find a relationship with dose.

Iron status and reproduction in US women: National Health and Nutrition Examination Survey, 1999-2006

Women experience significant changes in iron status throughout their reproductive lifespans. While this is evident in regions with high rates of malnutrition and infectious disease, the extent of reproductive-related changes is less well known in countries with low rates of iron deficiency anemia, such as the United States. The goal of this study is determine the relationship between women's reproductive variables (pregnancy, parity, currently breastfeeding, regular menstruation, hormonal contraceptive use, and age at menarche) and iron status (hemoglobin, ferritin, transferrin receptor, and % transferrin saturation) using an anthropological framework for interpreting the results. Data from women aged 18-49 were taken from the 1999-2006 US NHANES, a nationally representative cross-sectional sample of US women. Using multiple imputation and complex survey statistics, women's reproductive variables were regressed against indicators of iron status. Pregnant women had significantly poorer iron status, by most indicators, than non-pregnant women. All biomarkers demonstrated significantly lower iron levels with increasing parity. Women who were having regular periods had iron indicators that suggested decreased iron levels, while women who used hormonal contraceptives had iron indicators that suggested increased iron levels. Despite relatively good iron status and widespread availability of iron-rich foods in the US, women still exhibit patterns of iron depletion across several reproductive variables of interest. These results contribute to an ecological approach to iron status that seeks to understand variation in iron status, with the hopes that appropriate, population-specific recommendations can be developed to improve women's health.

Multiple micronutrient needs in pregnancy in industrialized countries

BACKGROUND

As nutritional deficiencies are known to lead to adverse pregnancy outcomes, a woman's nutritional status should be assessed preconceptionally with the goal of optimizing maternal, fetal and infant health. Worldwide micronutrient intakes do not fit pregnancy requirements, so that their supplementation is recommended from the beginning of pregnancy in most of the low- and middle-income countries. Conversely, data on multiple supplementation in developed countries appear few and controversial. Key Message: Although a balanced diet is generally accessible in industrialized countries, a switch to a high-fat and low-quality diet has led to an inadequate vitamin and mineral intake during pregnancy, so that recent data show the micronutrient intake and supplementation to be lower than recommended even in high-income countries, particularly for iron, folic acid, calcium and vitamin D.

CONCLUSIONS

Currently, even if there is insufficient evidence to support routine supplementation at the population level, except for periconceptional folate supplementation, these results need to be evaluated at an individual level in order to avoid nutritional deficiencies and to encourage women to establish healthful dietary practices prior to conception. The new goal in industrialized countries needs to be an individualized approach that takes account of the phenotypic, genotypic and metabolic differences among individuals of the same population.

Impact of maternal hemoglobin concentration on fetal outcomes in adolescent pregnant women

Background:

Studies on the association between maternal hemoglobin (Hb) concentration and adverse pregnancy outcome have been inconsistent. Many studies have shown the impact of Hb concentration on pregnancy outcomes in adult women; however, it is not revealed in adolescent pregnant women.

Objectives:

The aim of this study was to examine the effect of Hb concentration on birth outcomes in pregnant adolescents as a high-risk group.

Patients and Methods:

In this cross-sectional study, 312 healthy and nonsmoker adolescent pregnant women with gestational age (GA) of 37-40 weeks were chosen by random sampling, and were followed until delivery. A complete history was obtained from women. In addition, clinical examination and Hb test were performed. After birth, the associations between Hb concentration during pregnancy and birth outcomes were investigated. Statistical analyses were performed using SPSS software by t-test, chi-square and ANOVA.

Results:

In total, about 23.2 % were anemic, 58% had normal level of Hb (11-13.2 g/dL) and 18.8% had Hb > 13.2 g/dL. The mean birth weight was 3197.8 ± 398.25 grams and it was more in mothers with Hb = 10.5-12.5 g/dL than others (Hb < 10.5 or Hb > 12.5 g/dL) (P < 0.001). The lowest mean birth weight was found in mothers with Hb < 10.5 (3033.33 ± 422). Moreover, the mean birth weight of male newborns was more than females (P = 0.001). Eight percent of neonates had Apgar score less than eight. Low Apgar score in anemic group and mothers with high Hb concentration (Hb > 12.5 g/dL) was more than others.

Conclusions:

Abnormal Hb concentrations increase the risk of adverse birth outcomes such as low birth weight (LBW) and low Apgar scores in pregnant adolescents, so intensive care is recommended for this group of pregnant women.

Oral or parenteral iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors

BACKGROUND

Iron deficiency is a significant cause of deferral in people wishing to donate blood. If iron removed from the body through blood donation is not replaced, then donors may become iron deficient. All donors are screened at each visit for low haemoglobin (Hb) levels. However, some deferred blood donors do not return to donate. Deferred first-time donors are even less likely to return. Interventions that reduce the risk of provoking iron deficiency and anaemia in blood donors will therefore increase the number of blood donations. Currently, iron supplementation for blood donors is not a standard of care in many blood services. A systematic review is required to answer specific questions regarding the efficacy and safety of iron supplementation in blood donors.

OBJECTIVES

To assess the efficacy and safety of iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors.

SEARCH METHODS

We ran the search on 18 November 2013. We searched Cochrane Injuries Group Specialised Register, CENTRAL, PubMed, MEDLINE (OvidSP), EMBASE (OvidSP), CINAHL (EBSCO Host) and six other databases. We also searched clinical trials registers and screened guidelines reference lists.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing iron supplementation versus placebo or control, oral versus parenteral iron supplementation, iron supplementation versus iron-rich food supplements, and different doses, treatment durations and preparations of iron supplementation in healthy blood donors. Autologous blood donors were excluded.

DATA COLLECTION AND ANALYSIS

We combined data using random-effects meta-analyses. We evaluated heterogeneity using the I(2) statistic; we explored considerable heterogeneity (I(2) > 75%) in subgroup analyses. We carried out sensitivity analyses to assess the impact of trial quality on the results.

MAIN RESULTS

Thirty RCTs (4704 participants) met the eligibility criteria, including 19 comparisons of iron supplementation and placebo or control; one comparison of oral and parenteral iron supplementation; four comparisons of different doses of iron supplementation; one comparison of different treatment durations of iron supplementation; and 12 comparisons of different iron supplementation preparations.Many studies were of low or uncertain methodological quality and therefore at high or uncertain risk of bias. We therefore rated the quality of the evidence for our outcomes as moderate. There was a statistically significant reduction in deferral due to low haemoglobin in donors who received iron supplementation compared with donors who received no iron supplementation, both at the first donation visit after commencement of iron supplementation (risk ratio (RR) 0.34; 95% confidence interval (CI) 0.21 to 0.55; four studies; 1194 participants; P value < 0.0001) and at subsequent donations (RR 0.25; 95% CI 0.15 to 0.41; three studies; 793 participants; P value < 0.00001). Supplementation also resulted in significantly higher haemoglobin levels (mean difference (MD) 2.36 g/L; 95% CI 0.06 to 4.66; eight studies; 847 participants, P value =0.04), and iron stores, including serum ferritin (MD 13.98 ng/mL; 95% CI 8.92 to 19.03; five studies; 640 participants; P value < 0.00001) and transferrin saturation (MD 3.91%; 95% CI 2.02 to 5.80; four studies; 344 participants; P value < 0.0001) prior to further donation. The differences were maintained after subsequent donation(s).Adverse effects were widely reported and were more frequent in donors who received iron supplementation (RR 1.60; 95% CI 1.23 to 2.07; four studies; 1748 participants; P value = 0.0005). Adverse effects included constipation, diarrhoea, nausea, vomiting and taste disturbances, and some participants stopped treatment due to side effects.

AUTHORS' CONCLUSIONS

There is moderate quality evidence that rates of donor deferral due to low haemoglobin are considerably less in those taking iron supplements compared with those without iron supplementation, both at the first donation visit and at subsequent donation. Iron-supplemented donors also show elevated haemoglobin and iron stores. These beneficial effects are balanced by more frequent adverse events in donors who receive iron supplementation than in those who do not; this is likely to limit acceptability and compliance. The long-term effects of iron supplementation without measurement of iron stores are unknown. These considerations are likely to preclude widespread use of iron supplementation by tablets. Blood services may consider targeted use of supplementation in those at greatest risk of iron deficiency, personalised donation intervals and providing dietary advice.

Influence of host iron status on Plasmodium falciparum infection

Iron deficiency affects one quarter of the world's population and causes significant morbidity, including detrimental effects on immune function and cognitive development. Accordingly, the World Health Organization (WHO) recommends routine iron supplementation in children and adults in areas with a high prevalence of iron deficiency. However, a large body of clinical and epidemiological evidence has accumulated which clearly demonstrates that host iron deficiency is protective against falciparum malaria and that host iron supplementation may increase the risk of malaria. Although many effective antimalarial treatments and preventive measures are available, malaria remains a significant public health problem, in part because the mechanisms of malaria pathogenesis remain obscured by the complexity of the relationships that exist between parasite virulence factors, host susceptibility traits, and the immune responses that modulate disease. Here we review (i) the clinical and epidemiological data that describes the relationship between host iron status and malaria infection and (ii) the current understanding of the biological basis for these clinical and epidemiological observations.

Correcting haemoglobin cut-offs to define anaemia in high-altitude pregnant women in Peru reduces adverse perinatal outcomes

PURPOSE

To determine if correction of cut-offs of haemoglobin levels to define anaemia at high altitudes affects rates of adverse perinatal outcomes.

METHODS

Data were obtained from 161,909 mothers and newborns whose births occurred between 1,000 and 4,500 m above sea level (masl). Anaemia was defined with or without correction of haemoglobin (Hb) for altitude as Hb <11 g/dL. Correction of haemoglobin per altitude was performed according to guidelines from the World Health Organization. Rates of stillbirths and preterm births were also calculated.

RESULTS

Stillbirth and preterm rates were significantly reduced in cases of anaemia calculated after correction of haemoglobin for altitude compared to values obtained without Hb correction. At high altitudes (3,000-4,500 masl), after Hb correction, the rate of stillbirths was reduced from 37.7 to 18.3 per 1,000 live births (p < 0.01); similarly, preterm birth rates were reduced from 13.1 to 8.76 % (p < 0.01). The odds ratios for stillbirths and for preterm births were also reduced after haemoglobin correction.

CONCLUSION

At high altitude, correction of maternal haemoglobin should not be performed to assess the risks for preterm birth and stillbirth. In fact, using low altitude Hb cut-off is associated with predicting those at risk.

Influence of iron status on risk of maternal or neonatal infection and on neonatal mortality with an emphasis on developing countries

Infection is a major cause of neonatal death in developing countries. This review investigates whether host iron status affects the risk of maternal and/or neonatal infection, potentially contributing to neonatal death, and summarizes the iron acquisition mechanisms described for pathogens causing stillbirth, preterm birth, and congenital infection. In vitro evidence shows that iron availability influences the severity and chronicity of infections that cause these negative outcomes of pregnancy. In vivo evidence is lacking, as relevant studies of maternal iron supplementation have not assessed the effect of iron status on the risk of maternal and/or neonatal infection. Reducing iron-deficiency anemia among women is beneficial and should improve the iron stores of babies; moreover, there is evidence that iron status in young children predicts the risk of malaria and, possibly, the risk of invasive bacterial diseases. Caution with maternal iron supplementation is indicated in iron-replete women who may be at high risk of exposure to infection, although distinguishing between iron-replete and iron-deficient women is currently difficult in developing countries, where a point-of-care test is needed. Further research is indicated to investigate the risk of infection relative to iron status in mothers and babies in order to avoid iron intervention strategies that may result in detrimental birth outcomes in some groups of women.

Global, regional, and national trends in haemoglobin concentration and prevalence of total and severe anaemia in children and pregnant and non-pregnant women for 1995-2011: a systematic analysis of population-representative data

Background

Low haemoglobin concentrations and anaemia are important risk factors for the health and development of women and children. We estimated trends in the distributions of haemoglobin concentration and in the prevalence of anaemia and severe anaemia in young children and pregnant and non-pregnant women between 1995 and 2011.

Methods

We obtained data about haemoglobin and anaemia for children aged 6–59 months and women of childbearing age (15–49 years) from 257 population-representative data sources from 107 countries worldwide. We used health, nutrition, and household surveys; summary statistics from WHO's Vitamin and Mineral Nutrition Information System; and summary statistics reported by other national and international agencies. We used a Bayesian hierarchical mixture model to estimate haemoglobin distributions and systematically addressed missing data, non-linear time trends, and representativeness of data sources. We quantified the uncertainty of our estimates.

Findings

Global mean haemoglobin improved slightly between 1995 and 2011, from 125 g/L (95% credibility interval 123–126) to 126 g/L (124–128) in non-pregnant women, from 112 g/L (111–113) to 114 g/L (112–116) in pregnant women, and from 109 g/L (107–111) to 111 g/L (110–113) in children. Anaemia prevalence decreased from 33% (29–37) to 29% (24–35) in non-pregnant women, from 43% (39–47) to 38% (34–43) in pregnant women, and from 47% (43–51) to 43% (38–47) in children. These prevalences translated to 496 million (409–595 million) non-pregnant women, 32 million (28–36 million) pregnant women, and 273 million (242–304 million) children with anaemia in 2011. In 2011, concentrations of mean haemoglobin were lowest and anaemia prevalence was highest in south Asia and central and west Africa.

Interpretation

Children's and women's haemoglobin statuses improved in some regions where concentrations had been low in the 1990s, leading to a modest global increase in mean haemoglobin and a reduction in anaemia prevalence. Further improvements are needed in some regions, particularly south Asia and central and west Africa, to improve the health of women and children and achieve global targets for reducing anaemia.

Funding

Bill & Melinda Gates Foundation, Grand Challenges Canada, and the UK Medical Research Council.

The effect of intermittent antenatal iron supplementation on maternal and infant outcomes in rural Viet Nam: a cluster randomised trial

BACKGROUND

Anemia affects over 500 million women, and in pregnancy is associated with impaired maternal and infant outcomes. Intermittent antenatal iron supplementation is an attractive alternative to daily dosing; however, the impact of this strategy on infant outcomes remains unclear. We compared the effect of intermittent antenatal iron supplementation with daily iron supplementation on maternal and infant outcomes in rural Viet Nam.

METHODS AND FINDINGS

This cluster randomised trial was conducted in Ha Nam province, Viet Nam. 1,258 pregnant women (< 16 wk gestation) in 104 communes were assigned to daily iron-folic acid (IFA), twice weekly IFA, or twice weekly multiple micronutrient (MMN) supplementation. Primary outcome was birth weight. Mean birth weight was 3,148 g (standard deviation 416). There was no difference in the birth weights of infants of women receiving twice weekly IFA compared to daily IFA (mean difference [MD] 28 g; 95% CI -22 to 78), or twice weekly MMN compared to daily IFA (MD -36.8 g; 95% CI -82 to 8.2). At 32 wk gestation, maternal ferritin was lower in women receiving twice weekly IFA compared to daily IFA (geometric mean ratio 0.73; 95% CI 0.67 to 0.80), and in women receiving twice weekly MMN compared to daily IFA (geometric mean ratio 0.62; 95% CI 0.57 to 0.68), but there was no difference in hemoglobin levels. Infants of mothers who received twice weekly IFA had higher cognitive scores at 6 mo of age compared to those who received daily IFA (MD 1.89; 95% CI 0.23 to 3.56).

CONCLUSIONS

Twice weekly antenatal IFA or MMN did not produce a clinically important difference in birth weight, when compared to daily IFA supplementation. The significant improvement in infant cognitive outcomes at 6 mo of age following twice weekly antenatal IFA requires further exploration, and provides additional support for the use of intermittent, rather than daily, antenatal IFA in populations with low rates of iron deficiency.

TRIAL REGISTRATION

Australia New Zealand Clinical Trials Registry 12610000944033.

Completeness of reporting of setting and health worker cadre among trials on antenatal iron and folic acid supplementation in pregnancy: an assessment based on two Cochrane reviews

BACKGROUND

Poor reporting of medical trials has triggered the development of trial reporting standards within the scientific community. In addition to a description of the proposed intervention, adequate information about the trial setting and the group of health workers (cadre) delivering the intervention would allow a better understanding of the generalizability of the trial findings, facilitate replication of trial interventions and assist with assessment of trials for inclusion in systematic reviews. This study aims to determine the completeness of reporting for trial setting and cadre among trials included in two Cochrane reviews on iron and folic acid supplementation for women during pregnancy.

METHODS

From the 81 trials included in the two Cochrane reviews, we extracted data on the trial setting, including the facility type and geographic location, facility descriptors (i.e. level of care) and population descriptors (i.e. socioeconomic status); and the cadre, including professional qualifications, training and supervision.

RESULTS

Almost all studies reported the facility type and location (96%). However, only 68% included this information in the "methods" section of the report. Facility descriptors and population descriptors were less commonly reported (26% and 54% respectively). For 34% of the trials, we found some account of the type of health worker that delivered the intervention. Only 4% of the trials reported any training procedures.

CONCLUSIONS

Currently, complete reporting of setting and health worker cadre in iron and folic acid supplementation in pregnancy trials remains far from ideal, limiting assessments of the applicability of the trial findings. Trialists and journals need to ensure that this information is included in trial reports by adhering to and improving current reporting standards and by not making assumptions regarding readers' knowledge of the context and of the intervention delivery mechanism.

Accuracy of erythrogram and serum ferritin for the maternal anemia diagnosis (AMA): a phase 3 diagnostic study on prediction of the therapeutic responsiveness to oral iron in pregnancy

BACKGROUND

Pregnancy anemia remains as a public health problem, since the official reports in the 70's. To guide the treatment of iron-deficiency anemia in pregnancy, the haemoglobin concentration is the most used test in spite of its low accuracy, and serum ferritin is the most reliable test, although its cutoff point remains an issue.

METHODS/DESIGN

The aim of this protocol is to verify the accuracy of erythrocyte indices and serum ferritin (studied tests) for the diagnosis of functional iron-deficiency in pregnancy using the iron-therapy responsiveness as the gold-standard. This is an ongoing phase III accuracy study initiated in August 2011 and to be concluded in April 2013. The subjects are anemic pregnant women (haemoglobin concentration < 11.0 g/dL) attended at a low-risk prenatal care center in the Northeast of Brazil. The sample size (n 278) was calculated to estimate sensitivity of 90% and 80% of specificity with relative error of 10% and power of 95%. This study has a prospective design with a before-after intervention of 80 mg of daily oral iron during 90 days and will be analyzed as a delayed-type cross-sectional study. Women at the second trimester of pregnancy are being evaluated with clinical and laboratorial examinations at the enrollment and monthly. The 'responsiveness to therapeutic test with oral iron' (gold-standard) was defined to an increase of at least 0.55 Z-score in haemoglobin after 4 weeks of treatment and a total dose of 1200 mg of iron. At the study conclusion, sensitivities, specificities, predictive values, likelihood ratios and areas under the ROC (Receiver Operating Characteristic) curves of serum ferritin and erythrocyte indices (red blood cell count, haematocrit, haemoglobin concentration, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, red blood cell distribution width, reticulocyte count) will be tested. The compliance and adverse effects are considered confounding variables, since they are the main obstacles for the iron-therapy responsiveness.

DISCUSSION

This study protocol shows a new approach on iron-deficiency anemia in pregnancy from a functional point of view that could bring some insights about the diagnostic misclassifications arising from the dynamic physiologic changes during the gestational cycle.

TRIAL REGISTRATION

WHO International Clinical Trials Registry Platform U1111-1123-2605.

Daily oral iron supplementation during pregnancy

BACKGROUND

Iron and folic acid supplementation has been the preferred intervention to improve iron stores and prevent anaemia among pregnant women, and it may also 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.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (2 July 2012). We also searched the WHO International Clinical Trials Registry Platform (ICTRP) (2 July 2012) and contacted relevant organisations for the identification of ongoing and unpublished studies.

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.

MAIN RESULTS

We included 60 trials. Forty-three trials, involving more than 27,402 women, contributed data and compared the effects of daily oral supplements containing iron versus no iron or placebo.Overall, women taking iron supplements were less likely to have low birthweight newborns (below 2500 g) compared with controls (8.4% versus 10.2%, average risk ratio (RR) 0.81; 95% confidence interval (CI) 0.68 to 0.97, 11 trials, 8480 women) and mean birthweight was 30.81 g greater for those infants whose mothers received iron during pregnancy (average mean difference (MD) 30.81; 95% CI 5.94 to 55.68, 14 trials, 9385 women). Preventive iron supplementation reduced the risk of maternal anaemia at term by 70% (RR 0.30; 95% CI 0.19 to 0.46, 14 trials, 2199 women) and iron deficiency at term by 57% (RR 0.43; 95% CI 0.27 to 0.66, seven trials, 1256 women). Although the difference between groups did not reach statistical significance, women who received iron supplements were more likely than controls to report side effects (25.3% versus 9.91%) (RR 2.36; 95% CI 0.96 to 5.82, 11 trials, 4418 women), particularly at doses 60 mg of elemental iron or higher. 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 130g/L during pregnancy and at term. 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 reported malaria outcomes. There is no evidence that iron supplementation increases placental malaria. For some outcomes heterogeneity was higher than 50%.

AUTHORS' CONCLUSIONS

Prenatal supplementation with daily iron are effective to reduce the risk of low birthweight, and to prevent maternal anaemia and iron deficiency in pregnancy. Associated maternal side effects and particularly high Hb concentrations during pregnancy at currently used doses suggest the need to update recommendations on doses and regimens for routine iron supplementation.