Safety and benefits of antenatal oral iron supplementation in low-income countries: a review

Non-adherence to antenatal iron supplementation and its determinants among pregnant women in 35 sub-saharan African countries: a generalized linear mixed-effects modeling with robust Poisson regression analysis

BACKGROUND

Despite the integration of iron supplementation into routine antenatal care programs as a nutritional intervention to prevent anemia in pregnant women, the use of this supplement for the recommended duration remains low in sub-Saharan Africa (SSA). Evidence on maternal compliance with iron supplementation at the SSA level is lacking and most of the previous studies have been limited to specific geographic areas. Therefore, the current study used large population survey data from 35 SSA countries to estimate the pooled prevalence of non-adherence and its determinants.

METHODS

A secondary analysis was conducted using data from the demographic and health surveys across 35 SSA countries. After excluding women with missing data on the outcome variable, a weighted sample of 158,941 women who received iron supplementation during their recent pregnancy was included in the analysis. Forest plot was used to present the pooled and country-level rates of non-adherence to antenatal iron supplementation. A multilevel mixed-effects Poisson regression with robust variance was done to identify determinants of non-adherence.

RESULTS

The pooled prevalence of non-compliance to iron supplementation in SSA was 65.1% [95% CI: 64.9 - 65.3%], with the lowest level in Zambia (18%) and the highest in Burundi (97%). The analysis revealed that living in rural areas (aPR: 1.16, 95% CI: 1.13-1.19), lack of access to mass media (aPR: 1.10, 95% CI: 1.09-1.12), low household wealth (aPR: 1.11, 95% CI: 1.09-1.14), late (aPR: 1.19, 95% CI: 1.17-1.20) and frequent ANC visit (aPR: 1.28, 95% CI: 1.26, 1.29), women's employment status (aPR: 1.05, 95% CI: 1.03-1.06), husband illiteracy (aPR: 1.12, 95% CI: 1.10-1.13), and distance to a health facilities (aPR: 1.03, 95% CI: 1.01-1.05) were associated higher prevalence of non-adherence. Conversely, older maternal age was associated lower prevalence of non-compliance (aPR: 0.96, 95% CI: 0.94-0.97).

CONCLUSION

More than six out of ten pregnant women in SSA do not take iron supplements for the recommended period, with substantial variations across the countries. The level of non-adherence was significantly varied by women's sociodemographic and reproductive characteristics. This urges the need for strengthening community health interventions and other existing programs to reach women in rural and economically disadvantaged settings. Furthermore, promoting antenatal care services through mass media and community-based health education strategies is key for scaling up the utilization of the supplement. Our results also suggest the importance of establishing the community-based distribution of iron supplements to address women with limited access to the healthcare system.

Screening and treatment practices for iron deficiency in anaemic pregnant women: A cross-sectional survey of healthcare workers in Nigeria

BACKGROUND

Iron deficiency anaemia in pregnancy is a significant contributor to maternal and perinatal morbidity and mortality globally. Despite international and national guidelines for its screening and treatment, knowledge and prescription practices of healthcare providers vary.

AIM

To determine maternal healthcare workers' screening and treatment practices for iron deficiency in anaemic pregnancy women in two states in Nigeria.

METHODOLOGY

This cross-sectional study sampled maternal healthcare workers from 84 randomly selected public health facilities in Lagos and Kano States. Data on methods of diagnosis and prescription practices for iron deficiency anaemia were collected using a self-administered questionnaire. Means and percentages were reported using probability weights, and a comparison of practices of anaemia treatment between doctors and nurses/midwives was done using Chi-square test or Fishers exact.

RESULTS

Of the 467 maternal healthcare workers surveyed (232 from Lagos, 235 from Kano), 40.0% were doctors, 54.0% nurses or midwives and 6.0% community health extension workers. In the sample, 27.6% always and 58.7% sometimes screened anaemic pregnant women for iron deficiency; among these, 84.7% screened using complete blood count. Oral iron for treatment of iron deficiency anaemia was prescribed by 96.9%. Intravenous iron for treatment was prescribed by 30.2%, but by only by 18.6% as first-line drug (as iron dextran by 69.3% and as iron sucrose by 31.5% of intravenous iron prescribers). Commonest reasons for low usage of intravenous iron were cost and need for venepuncture. Fifty-three percent of maternal healthcare workers' prescribed iron supplements for anaemia during concomitant infection, with the prescription practice similar among doctors versus nurse/midwives (p = 0.074).

CONCLUSION

We found suboptimal levels of screening for iron deficiency among anaemic pregnant women. Iron deficiency anaemia in pregnancy is almost exclusively treated with oral iron by maternal healthcare workers in the two Nigerian states, similarly between doctors and nurses/midwives. Further research into potential reasons for low screening for iron deficiency and low use of intravenous iron are needed.

Associations of Maternal Nutritional Status and Supplementation with Fetal, Newborn, and Infant Outcomes in Low-Income and Middle-Income Settings: An Overview of Reviews

BACKGROUND/OBJECTIVES

Despite advances in maternal nutritional knowledge, the effect of maternal diet, micronutrient status and undernutrition, and the effect of maternal supplementation on fetal, neonatal and infant outcomes still have gaps in the literature. This overview of reviews is intended to assess the available information on these issues and identify the main maternal nutritional factors associated with offspring outcomes in low- and middle-income countries as possible targets for public health interventions.

METHODS

The literature search was performed in Medline (PubMed) and Cochrane Library datasets in June 2024. Pre-specified outcomes in offspring were pooled using standard meta-analytical methods.

RESULTS

We found consistent evidence on the impact of maternal undernutrition indicated by low body mass index (BMI), mid-upper arm circumference (MUAC), and stature, but not of individual micronutrient status, on intrauterine-growth retardation, preterm birth, low birth weight, and small for gestational age, with research showing a possible effect of maternal undernutrition in later child nutritional status. Studies on micronutrient supplementation showed possible beneficial effects of iron, vitamin D, and multiple micronutrients on birthweight and/or decreasing small for gestational age, as well as a possible effect of calcium on preterm birth reduction. Interventions showing more consistent beneficial outcomes were balanced protein-energy and lipid base supplements, which demonstrated improved weight in newborns from supplemented mothers and a decreased risk of adverse neonatal outcomes.

CONCLUSIONS

Further research is needed to identify the benefits and risks of maternal individual micronutrient supplementation on neonatal and further child outcomes.

Ten2Twenty-Ghana: a randomised controlled trial on the efficacy of multiple micronutrient-fortified biscuits on the micronutrient status of adolescent girls

Adolescent girls are an important target group for micronutrient interventions particularly in Sub-Saharan Africa where adolescent pregnancy and micronutrient deficiencies are common. When consumed in sufficient amounts and at levels appropriate for the population, fortified foods may be a useful strategy for this group, but little is known about their effectiveness and timing (regarding menarche), particularly in resource-poor environments. We evaluated the effect of consuming multiple micronutrient-fortified biscuits (MMB), sold in the Ghanaian market, 5 d/week for 26 weeks compared with unfortified biscuits (UB) on the micronutrient status of female adolescents. We also explored to what extent the intervention effect varied before or after menarche. Ten2Twenty-Ghana was a 26-week double-blind, randomised controlled trial among adolescent girls aged 10-17 years (n 621) in the Mion District, Ghana. Biomarkers of micronutrient status included concentrations of Hb, plasma ferritin (PF), soluble transferrin receptor (TfR) and retinol-binding protein (RBP), including body-iron stores. Intention-to-treat analysis was supplemented by protocol-specific analysis. We found no effect of the intervention on PF, TfR and RBP. MMB consumption did not affect anaemia and micronutrient deficiencies at the population level. MMB consumption increased the prevalence of vitamin A deficiency by 6·2 % (95 % CI (0·7, 11·6)) among pre-menarche girls when adjusted for baseline micronutrient status, age and height-for-age Z-score, but it decreased the prevalence of deficient/low vitamin A status by -9·6 % (95 % CI (-18·9, -0·3)) among post-menarche girls. Consuming MMB available in the market did not increase iron status in our study, but reduced the prevalence of deficient/low vitamin A status in post-menarcheal girls.

Review of intervention products for use in the prevention and control of anemia

Anemia remains a major public health problem, especially in low- and middle-income countries. The World Health Organization recommends several interventions to prevent and manage anemia in vulnerable population groups, including young children, menstruating adolescent girls and women, and pregnant and postpartum women. Daily iron supplementation reduces the risk of anemia in infants, children, and pregnant women, and intermittent iron supplementation reduces anemia risk in menstruating girls and women. Micronutrient powders reduce the risk of anemia in children. Fortifying wheat flour with iron reduces the risk of anemia in the overall population, whereas the effect of fortifying maize flour and rice is still uncertain. Regarding non-nutrition-related interventions, malaria treatment and deworming have been reported to decrease anemia prevalence. Promising interventions to prevent anemia include vitamin A supplementation, multiple micronutrient supplementation for pregnant women, small-quantity lipid-based supplements, and fortification of salt with iodine and iron. Future research could address the efficacy and safety of different iron supplementation formulations, identify the most bioavailable form of iron for fortification, examine adherence to supplementation regimens and fortification standards, and investigate the effectiveness of integrating micronutrient, helminth, and malaria control programs.

Quantifying differences in iron deficiency-attributable anemia during pregnancy and postpartum

Pregnant women in resource-limited settings are highly susceptible to anemia and iron deficiency, but the etiology of postpartum anemia remains poorly defined. To inform the optimal timing for anemia interventions, changes in iron deficiency-attributable anemia through pregnancy and postpartum need to be understood. In 699 pregnant Papua New Guinean women attending their first antenatal care appointment and following up at birth and 6 and 12 months postpartum, we undertake logistic mixed-effects modeling to determine the effect of iron deficiency on anemia and population attributable fractions, calculated from odds ratios, to quantify the contribution of iron deficiency to anemia. Anemia is highly prevalent during pregnancy and 12 months postpartum, with iron deficiency increasing the odds of anemia during pregnancy and, to a lesser extent, postpartum. Iron deficiency accounts for ≥72% of anemia during pregnancy and 20%-37% postpartum. Early iron supplementation during and between pregnancies could break the cycle of chronic anemia in women of reproductive age.

Sociocultural and drug-related factors associated with adherence to iron-folic acid supplementation among pregnant women - A mixed-methods study

BACKGROUND

The National Family Health Survey of India (NFHS-5) revealed a lapse in the advancement of mitigating anemia despite free supplementation of iron-folic acid tablets (IFAT) and improvement in IFAT coverage during pregnancy. The local sociocultural beliefs and community perspective toward IFAT are pivotal in reducing the gap between IFAT coverage and consumption. Hence, we proposed the study to assess adherence to IFAT among rural pregnant women and explore the associated factors.

MATERIALS AND METHODS

The present study was conducted as a mixed-methods study with a sequential exploratory design in a rural setting of the Model Rural Health Research Unit (MRHRU) from October 2020 to May 2021. Ten focus group discussions (FGDs; 8 - antenatal women, 1 - mother/mother-in-law, and 1 - health care worker) were conducted, and framework analysis was done to identify themes followed by a quantitative survey with a semi-structured questionnaire among antenatal women (n = 236). Logistic regression was used to analyze factors associated with adherence.

RESULTS

The major themes that emerged from FGDs were the sociocultural factors (gender norms, communal fallacies), lack of awareness, and drug-related factors (unpalatability, misperceptions, and experienced side effects). Around 57% were adherent to IFAT. Side effects experienced on IFAT intake (P = 0.001, OR = 2.33), misconceptions regarding IFAT, like weight gain in IFAT use (P = 0.001, OR = 2.86), a big baby with IFAT use (P = 0.000, OR = 5.93) negatively influenced adherence.

CONCLUSIONS

The significant gaps between IFAT coverage and consumption surrounded the unpleasant odor and stench of IFAT, side effects, lack of individualized counseling, and misperceptions regarding IFAT use.

The effect of iron supplementation on maternal iron deficiency anemia does not differ by baseline anemia type among Tanzanian pregnant women without severe iron deficiency anemia

PURPOSE

Whether anemia type modifies the risk of pregnancy and newborn outcomes and the effectiveness of iron supplementation is unclear. We examined the association of iron deficiency anemia (IDA) and non-iron deficiency anemia (NIDA) on the risks of these outcomes and the extent to which anemia type modifies the impact of prenatal iron supplementation.

METHODS

This was a secondary analysis of a placebo-controlled trial of iron supplementation among 1450 HIV-negative women in Tanzania. Eligibility criteria included gestational age < 27 weeks, hemoglobin > 85 g/L, and ferritin > 12 µg/L. Individuals were categorized as non-anemia, IDA or NIDA using hemoglobin, ferritin and CRP. Analyses were conducted using regression models and likelihood ratio tests.

RESULTS

Compared to the non-anemia group, delivery hemoglobin was lower by 15 g/L (95% CI 10.9, 19.3) in the baseline IDA group, and 7.3 g/L (95% CI 3.1, 11.5) in the baseline NIDA group. The RRs of anemia severity, iron deficiency, placental malaria, stillbirths, perinatal mortality, birthweight, and preterm birth were not different among women in the baseline NIDA group (vs. non-anemia) compared to the baseline IDA group (vs. non-anemia). The difference in the mean delivery hemoglobin for iron supplementation and placebo arms was 8 g/L (95% CI 6, 11) in the non-anemia group, 7 g/L (95% CI 2, 13) in the NIDA group, and 16 g/L (95% CI 10, 22) in the IDA group.

CONCLUSION

Iron supplementation is effective even among pregnant women with NIDA.

TRIAL REGISTRATION

NCT01119612 (May 7, 2010).

Maternal nutritional status, decision-making autonomy and the nutritional status of adolescent girls: a cross-sectional analysis in the Mion District of Ghana

A mother's nutritional status and participation in household decision-making, a proxy for empowerment, are known determinants of improved nutrition and health outcomes for infants and young children; however, little is known about the association among adolescents. We examined the association between maternal nutritional status, decision-making autonomy and adolescent girls' nutritional status. We analysed data of 711 mother-adolescent girl pairs aged 10-17 years from the Mion District, Ghana. Maternal nutritional status and decision-making autonomy were the independent variables while the outcomes were adolescent girls' nutritional status as defined by anaemia, stunting and body mass index-for-age Z-score categories. Girl-level (age, menarche status and the frequency of animal-source food consumption), mother-level (age, education level, and monthly earnings) and household-level (wealth index, food security status and family size) covariates were adjusted for in the analysis. All associations were examined with hierarchical survey logistic regression. There was no association between maternal height and adolescent girls being anaemic, underweight or overweight/obese. Increasing maternal height reduced the odds of being stunted [adjusted odds ratio (OR) 0⋅92, 95 % CI (0⋅89, 0⋅95)] for the adolescent girl. Maternal overweight/obesity was positively associated with the girl being anaemic [OR 1⋅35, 95 % CI (1⋅06, 1⋅72)]. The adolescent girl was more than five times likely to be thin [OR 5⋅28, 95 % CI (1⋅64-17⋅04)] when the mother was underweight. Maternal decision-making autonomy was inversely associated with stunting [OR 0⋅88, 95 % CI (0⋅79, 0⋅99)] among the girls. Our findings suggest that intergenerational linkages of a mother's nutritional status are not limited to childhood but also during adolescence.

Obstetric red cell transfusion in a high-volume tertiary hospital: a retrospective cohort study

Introduction

Red cell transfusion is expensive and not without risks. Despite the availability of transfusion guidelines, studies report a wide interhospital variation in transfusion rates. This retrospective cohort study was conducted to define the incidence of red cell transfusion in a multi-ethnic obstetric population and to evaluate current transfusion practice with regard to indications and appropriateness.

Methods

All parturients who delivered a live or stillbirth in the period 2014-2015 and who received allogeneic blood transfusion during pregnancy and up to six weeks postnatally were identified. Their medical records were reviewed to extract the relevant demographic, obstetric and transfusion data. Descriptive analysis of data was performed using IBM SPSS Statistics software.

Results

Out of 23,456 parturients who delivered in the study period, 760 were administered red cell transfusion, resulting in a transfusion rate of 3.2% or 32 in 1,000 maternities. A total of 1,675 red cell units were utilised in 863 transfusion episodes. Major indications for transfusion were anaemia in pregnancy (49.2%) and postpartum haemorrhage secondary to an atonic uterus. Transfusion was more frequently associated with caesarean than vaginal births (4.9% vs. 2.4%). About 14% of transfusions were initiated with pre-transfusion haemoglobin (Hb) ≥ 8.0 g/dL, whereas 37% of transfusions resulted in post-transfusion Hb > 9.0 g/dL.

Conclusion

The incidence of red cell transfusion was 3.2% in a multiethnic obstetric population. Patient blood management strategies should focus on optimising antenatal anaemia, reducing blood loss during delivery and eliminating inappropriate transfusion.

Antenatal Iron-Rich Food Intervention Prevents Iron-Deficiency Anemia but Does Not Affect Serum Hepcidin in Pregnant Women

BACKGROUND

Limited evidence supports the efficacy of iron-rich foods (IRFs) in improving iron status during pregnancy.

OBJECTIVES

The study aims to evaluate the effect of IRFs on iron status and biomarkers of iron metabolism in the third trimester of pregnancy.

METHODS

A total of 240 pregnant women at 11-13 wk of gestation without iron-deficiency anemia (IDA) in South China were recruited to this single-blind clinical trial [non-IDA referred to both hemoglobin (Hb) ≥110g/L and serum ferritin (SF) ≥15ng/mL],  randomly assigned to 1) control, 2) IRFs containing 20 mg iron/d (IRF-20), or 3) IRFs containing 40 mg iron/d (IRF-40). The IRFs were consumed 3 days a week, including pork liver, chicken/duck blood, soybean, and agaric. The IRFs started at recruitment and ended in the predelivery room. Primary outcome included anemia (Hb <110 g/L), iron deficiency (ID, definition 1: SF <15 ng/mL; definition 2: SF <12 ng/mL), and IDA (ID and Hb <110 g/L). Secondary outcome was plasma Hb and iron indices, including SF, serum hepcidin, and iron.

RESULTS

All participants who completed the trial with full data (n = 170) were included in the analysis. At the endline, both intervention groups showed lower ID and IDA rates than control. Specifically, IRF-40 showed a lower ID (SF <12 ng/mL) rate than control (9.0% compared with 22.8%, P = 0.022). For IDA by definition 1, the incidence in IRF-40 was lower than that in control (1.9% compared with 8.9%, P = 0.045). For IDA by definition 2, the incidence in IRF-20 was lower than that in control (3.9% compared with 17.9%, P = 0.049). Moreover, IRF-20 showed higher SF concentrations than control (P = 0.039). No effects of IRFs on anemia (P = 0.856), plasma Hb (P = 0.697), serum hepcidin (P = 0.311), and iron (P = 0.253) concentrations were observed. The assessed iron intakes were 22.2 mg/d in IRF-20 and 25.0 mg/d in IRF-40, respectively.

CONCLUSIONS

Antenatal IRFs reduce the risk of ID and IDA in late pregnancy, although the present results are inadequate to confirm an ideal dosage (No. ChiCTR1800017574).

Gestational Iron Supplementation Improves Fetal Outcomes in a Rat Model of Prenatal Alcohol Exposure

Prenatal alcohol exposure causes neurodevelopmental disability and is associated with a functional iron deficiency in the fetus and neonate, even when the mother consumes an apparently iron-adequate diet. Here, we test whether gestational administration of the clinically relevant iron supplement Fer-In-Sol mitigates alcohol’s adverse impacts upon the fetus. Pregnant Long-Evans rats consumed an iron-adequate diet and received 5 g/kg alcohol by gavage for 7 days in late pregnancy. Concurrently, some mothers received 6 mg/kg oral iron. We measured maternal and fetal weights, hematology, tissue iron content, and oxidative damage on gestational day 20.5. Alcohol caused fetal anemia, decreased fetal body and brain weight, increased hepatic iron content, and modestly elevated hepatic malondialdehyde (p’s < 0.05). Supplemental iron normalized this brain weight reduction in alcohol-exposed males (p = 0.154) but not female littermates (p = 0.031). Iron also reversed the alcohol-induced fetal anemia and normalized both red blood cell numbers and hematocrit (p’s < 0.05). Iron had minimal adverse effects on the mother or fetus. These data show that gestational iron supplementation improves select fetal outcomes in prenatal alcohol exposure (PAE) including brain weight and hematology, suggesting that this may be a clinically feasible approach to improve prenatal iron status and fetal outcomes in alcohol-exposed pregnancies.

Maternal micronutrient status and its association with sociodemographic, maternal, and dietary factors in a cross-sectional study

AIM

Maternal serum micronutrient status can have a significant impact on short- and long-term outcomes for mother and offspring. The aim of this study was to examine the associations of maternal serum folate, ferritin, and vitamin B₁₂ status with maternal and dietary factors.

METHODS

This observational cross-sectional study was carried out with 165 healthy pregnant women at least 18 years of age with a singleton pregnancy. Maternal nutrient intake was determined by 24-hour dietary recall method and supplement records. Multivariable analyses using stepwise linear regression models were performed to associations of dietary intakes and maternal serum status.

RESULTS

There was a difference between the lowest and highest quartile of maternal serum folate, ferritin, and vitamin B₁₂ status and maternal characteristics and dietary, and total intakes of nutrients (p < 0.05). Multivariable stepwise linear regression analysis showed the predictors of serum folate status were dietary folate equivalent, dietary folate, total vitamin B₆ and iron intake. Primer predictors of serum ferritin and vitamin B₁₂ status were dietary protein intake (p < 0.05).

CONCLUSION

Our findings support existing recommendations that folic acid supplementation should be prescribed to achieve optimal serum folate status during pregnancy. However, dietary protein intake is important to provide optimal maternal serum vitamin B₁₂ and ferritin status.

Correlation Between High Serum Ferritin Level and Gestational Diabetes: A Systematic Review

Gestational diabetes mellitus (GDM) is a growing pregnancy-related health problem all over the world. It has been noticed that women with high serum ferritin levels have a strong relationship with GDM by increased insulin resistance and increased insulin secretion from the pancreas resulting in pancreatic beta-cell exhaustion. Heme iron is also responsible for increasing the body's iron store and hence causing oxidative injury to pancreatic cells. In this systematic review, we researched the association between high serum ferritin levels and GDM. Three databases were consulted for articles related to GDM and high ferritin. These include Medical Literature Analysis and Retrieval System Online (MEDLINE), PubMed, and PubMed Central (PMC). Additional articles were retrieved from the institutional database. After filtering, 10 articles were finally selected, and quality was checked using the Joanna Briggs Institute (JBI) Critical Appraisal quality check tool. Serum iron biomarkers including ferritin, iron, and soluble transferrin receptor (sTfR) were measured. Our systematic review indicates that high maternal serum ferritin has a significant role in the development of GDM. We have also noticed the importance of sTfR and serum hepcidin as biomarkers to monitor high ferritin levels. Our study also observed a positive relationship between high heme iron intake and gestational diabetes mellitus. Therefore, more research is required to understand this relationship to identify populations at risk.

Iron deficiency anaemia in sub-Saharan Africa: a review of current evidence and primary care recommendations for high-risk groups

The epidemiology of iron deficiency anaemia in sub-Saharan Africa differs from that in other parts of the world. The low-quality diets prevalent in this region are a poor source of iron, the population is frequently exposed to infection, and demographic characteristics result in a greater prevalence of people at high risk of iron deficiency anaemia than in other parts of the world. We herein review the causes, disease burden, and consequences of iron deficiency anaemia in the general population in this region, and current policies and interventions for its control. The current debate is dominated by concerns about the safety of iron interventions, namely regarding its effects on malaria and other infectious diseases. However, universal antenatal iron supplementation and delayed cord clamping are safe interventions and stand out for their potential to improve maternal and infant health. Effective infection control is a precondition to safe and efficacious iron interventions in children. Greater emphasis should be given to approaches aiming to reduce iron loss due to helminth infections and menstruation, alongside interventions to increase iron intake. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

The critical roles of iron during the journey from fetus to adolescent: Developmental aspects of iron homeostasis

Iron is indispensable for human life. However, it is also potentially toxic, since it catalyzes the formation of harmful oxidative radicals in unbound form and may facilitate pathogen growth. Therefore, iron homeostasis needs to be tightly regulated. Rapid growth and development require large amounts of iron, while (especially young) children are vulnerable to infections with iron-dependent pathogens due to an immature immune system. Moreover, unbalanced iron status early in life may have effects on the nervous system, immune system and gut microbiota that persist into adulthood. In this narrative review, we assess the critical roles of iron for growth and development and elaborate how the body adapts to physiologically high iron demands during the journey from fetus to adolescent. As a first step towards the development of clinical guidelines for the management of iron disorders in children, we summarize the unmet needs regarding the developmental aspects of iron homeostasis.

Effects of vitamin and mineral supplementation during pregnancy on maternal, birth, child health and development outcomes in low- and middle-income countries: A systematic review

Background

Almost two billion people who are deficient in vitamins and minerals are women and children in low- and middle-income countries (LMIC). These deficiencies are worsened during pregnancy due to increased energy and nutritional demands, causing adverse outcomes in mother and child. To reduce micronutrient deficiencies, several strategies have been implemented, including diet diversification, large-scale and targeted fortification, staple crop bio-fortification and micronutrient supplementation.

Objectives

To evaluate and summarize the available evidence on the effects of micronutrient supplementation during pregnancy in LMIC on maternal, fetal, child health and child development outcomes. This review will assess the impact of single micronutrient supplementation (calcium, vitamin A, iron, vitamin D, iodine, zinc, vitamin B12), iron-folic acid (IFA) supplementation, multiple micronutrient (MMN) supplementation, and lipid-based nutrient supplementation (LNS) during pregnancy.

Search Methods

We searched papers published from 1995 to 31 October 2019 (related programmes and good quality studies pre-1995 were limited) in CAB Abstracts, CINAHL, Cochrane Central Register of Controlled Trials, Embase, International Initiative for Impact Evaluations, LILACS, Medline, POPLINE, Web of Science, WHOLIS, ProQuest Dissertations & Theses Global, R4D, WHO International Clinical Trials Registry Platform. Non-indexed grey literature searches were conducted using Google, Google Scholar, and web pages of key international nutrition agencies.

Selection Criteria

We included randomized controlled trials (individual and cluster-randomized) and quasi-experimental studies that evaluated micronutrient supplementation in healthy, pregnant women of any age and parity living in a LMIC. LMIC were defined by the World Bank Group at the time of the search for this review. While the aim was to include healthy pregnant women, it is likely that these populations had one or more micronutrient deficiencies at baseline; women were not excluded on this basis.

Data Collection and Analysis

Two authors independently assessed studies for inclusion and risk of bias, and conducted data extraction. Data were matched to check for accuracy. Quality of evidence was assessed using the GRADE approach.

Main Results

A total of 314 papers across 72 studies (451,723 women) were eligible for inclusion, of which 64 studies (439,649 women) contributed to meta-analyses. Seven studies assessed iron-folic acid (IFA) supplementation versus folic acid; 34 studies assessed MMN vs. IFA; 4 studies assessed LNS vs. MMN; 13 evaluated iron; 13 assessed zinc; 9 evaluated vitamin A; 11 assessed vitamin D; and 6 assessed calcium. Several studies were eligible for inclusion in multiple types of supplementation. IFA compared to folic acid showed a large and significant (48%) reduction in the risk of maternal anaemia (average risk ratio (RR) 0.52, 95% CI 0.41 to 0.66; studies = 5; participants = 15,540; moderate-quality evidence). As well, IFA supplementation demonstrated a smaller but significant, 12% reduction in risk of low birthweight (LBW) babies (average RR 0.88, 95% CI 0.78 to 0.99; studies = 4; participants = 17,257; high-quality evidence). MMN supplementation was defined as any supplement that contained at least 3 micronutrients. Post-hoc analyses were conducted, where possible, comparing the differences in effect of MMN with 4+ components and MMN with 3 or 4 components. When compared to iron with or without FA, MMN supplementation reduced the risk of LBW by 15% (average RR 0.85, 95% CI 0.77 to 0.93; studies = 28; participants = 79,972); this effect was greater in MMN with >4 micronutrients (average RR 0.79, 95% CI 0.71 to 0.88; studies = 19; participants = 68,138 versus average RR 1.01, 95% CI 0.92 to 1.11; studies = 9; participants = 11,834). There was a small and significant reduction in the risk of stillbirths (average RR 0.91; 95% CI 0.86 to 0.98; studies = 22; participants = 96,772) and a small and significant effect on the risk of small-for-gestational age (SGA) (average RR 0.93; 95% CI 0.88 to 0.98; studies = 19; participants = 52,965). For stillbirths and SGA, the effects were greater among those provided MMN with 4+ micronutrients. Children whose mothers had been supplemented with MMN, compared to IFA, demonstrated a 16% reduced risk of diarrhea (average RR 0.84; 95% CI 0.76 to 0.92; studies = 4; participants = 3,142). LNS supplementation, compared to MMN, made no difference to any outcome; however, the evidence is limited. Iron supplementation, when compared to no iron or placebo, showed a large and significant effect on maternal anaemia, a reduction of 47% (average RR 0.53, 95% CI 0.43 to 0.65; studies = 6; participants = 15,737; moderate-quality evidence) and a small and significant effect on LBW (average RR 0.88, 95% CI 0.78 to 0.99; studies = 4; participants = 17,257; high-quality evidence). Zinc and vitamin A supplementation, each both compared to placebo, had no impact on any outcome examined with the exception of potentially improving serum/plasma zinc (mean difference (MD) 0.43 umol/L; 95% CI -0.04 to 0.89; studies = 5; participants = 1,202) and serum/plasma retinol (MD 0.13 umol/L; 95% CI -0.03 to 0.30; studies = 6; participants = 1,654), respectively. When compared to placebo, vitamin D supplementation may have reduced the risk of preterm births (average RR 0.64; 95% CI 0.40 to 1.04; studies = 7; participants = 1,262), though the upper CI just crosses the line of no effect. Similarly, calcium supplementation versus placebo may have improved rates of pre-eclampsia/eclampsia (average RR 0.45; 95% CI 0.19 to 1.06; studies = 4; participants = 9,616), though the upper CI just crosses 1.

Authors' Conclusions

The findings suggest that MMN and vitamin supplementation improve maternal and child health outcomes, including maternal anaemia, LBW, preterm birth, SGA, stillbirths, micronutrient deficiencies, and morbidities, including pre-eclampsia/eclampsia and diarrhea among children. MMN supplementation demonstrated a beneficial impact on the most number of outcomes. In addition, MMN with >4 micronutrients appeared to be more impactful than MMN with only 3 or 4 micronutrients included in the tablet. Very few studies conducted longitudinal analysis on longer-term health outcomes for the child, such as anthropometric measures and developmental outcomes; this may be an important area for future research. This review may provide some basis to guide continual discourse around replacing IFA supplementation with MMN along with the use of single micronutrient supplementation programs for specific outcomes.

Predictors of iron consumption for at least 90 days during pregnancy: Findings from National Demographic Health Survey, Pakistan (2017-2018)

BACKGROUND

Iron supplementation is considered an imperative strategy for anemia prevention and control during pregnancy in Pakistan. Although there is some evidence on the predictors of iron deficiency anemia among Pakistani women, there is a very limited understanding of factors associated with iron consumption among Pakistani pregnant women. Thus, this study aimed to investigate the predictors of iron consumption for at least ≥90 days during pregnancy in Pakistan.

METHODS

We analyzed dataset from the nationally representative Pakistan Demographic Health Survey 2017-2018. The primary outcome of the current study was the consumption of iron supplementation for ≥90 days during the pregnancy of the last birth. Women who had last childbirth 5 years before the survey and who responded to the question of iron intake were included in the final analysis (n = 6370). We analyzed the data that accounted for complex sampling design by including clusters, strata, and sampling weights.

RESULTS

Around 30% of the women reported consumed iron tablets for ≥90 days during their last pregnancy. In the multivariable logistic regression analysis, we found that factors such as women's age (≥ 25 years) (adjusted prevalence ratio (aPR) = 1.52; 95% CI: 1.42-1.62)], wealth index (rich/richest) (aPR = 1.25; [95% CI: 1.18-1.33]), primary education (aPR = 1.33; [95% CI: 1.24-1.43), secondary education (aPR = 1.34; [95% CI: 1.26-1.43), higher education (aPR = 2.13; [95% CI: 1.97-2.30), women's say in choosing husband (aPR = 1.68; [95% CI: 1.57-1.80]), ≥ five antenatal care visits (aPR =2.65; [95% CI (2.43-2.89]), history of the last Caesarian-section (aPR = 1.29; [95% CI: 1.23-1.36]) were significantly associated with iron consumption for ≥90 days.

CONCLUSION

These findings demonstrate complex predictors of iron consumption during pregnancy in Pakistan. There is a need to increase the number of ANC visits and the government should take necessary steps to improve access to iron supplements by targeting disadvantaged and vulnerable women who are younger, less educated, poor, and living in rural areas.

Oxidative Stress at Birth Is Associated with the Concentration of Iron and Copper in Maternal Serum

Oxidative stress (OS) in the foetal and neonatal periods leads to many disorders in newborns and in later life. The nutritional status of pregnant women is considered to be one of the key factors that triggers OS. We investigated the relationship between the concentration of selected mineral elements in the blood of pregnant women and the concentration of 3′nitrotyrosine (3′NT) as a marker of OS in the umbilical cord blood of newborns. The study group consisted of 57 pregnant women and their newborn children. The concentrations of magnesium (Mg), calcium (Ca), iron (Fe), zinc (Zn) and copper (Cu) in maternal serum (MS) were measured by the flame atomic absorption/emission spectrometry (FAAS/FAES) method. The concentration of 3′NT in umbilical cord serum (UCS) of newborns was determined by the ELISA method. A positive correlation between MS Fe and UCS 3′NT in male newborns was shown (rho = 0.392, p = 0.053). Significantly higher UCS 3′NT was demonstrated in newborns, especially males, whose mothers were characterized by MS Fe higher than 400 μg/dL compared to those of mothers with MS Fe up to 300 μg/dL (p < 0.01). Moreover, a negative correlation between the MS Cu and UCS 3′NT in male newborns was observed (rho = −0.509, p = 0.008). Results of the study showed the need to develop strategies to optimize the nutritional status of pregnant women. Implementation of these strategies could contribute to reducing the risk of pre- and neonatal OS and its adverse health effects in the offspring.

Antenatal iron supplementation, FGF23, and bone metabolism in Kenyan women and their offspring: secondary analysis of a randomized controlled trial

BACKGROUND

Fibroblast growth factor-23 (FGF23) regulates body phosphate homeostasis primarily by increasing phosphaturia. It also acts as a vitamin D-regulating hormone. Maternal iron deficiency is associated with perturbed expression and/or regulation of FGF23 and hence might be implicated in the pathogenesis of hypophosphatemia-driven rickets in their offspring.

OBJECTIVES

We aimed to determine the effect of antenatal oral iron supplementation on FGF23 concentration and maternal and infant markers of bone-mineral regulation.

METHODS

We performed a secondary analysis of a trial in which 470 rural Kenyan women with singleton pregnancies and hemoglobin concentrations ≥ 90 g/L were randomly allocated to daily, supervised supplementation with 60 mg elemental iron as ferrous fumarate or placebo from 13-23 weeks of gestation until 1 mo postpartum. As previously reported, iron supplementation improved iron status in mothers and neonates. For the present study, we reanalyzed all available plasma samples collected in mothers and neonates at birth, with primary outcomes being concentrations of FGF23, measured by 2 assays: 1 that detects intact hormone and C-terminal cleavage products (total-FGF23) and another that detects the intact hormone only (intact-FGF23).

RESULTS

Analysis was performed on 433 women (n = 216, iron group; n = 217, placebo group) and 414 neonates (n = 207, iron group; n = 207, placebo group). Antenatal iron supplementation reduced geometric mean total-FGF23 concentrations in mothers and neonates by 62.6% (95% CI: 53.0%, 70.3%) and 15.2% (95% CI: -0.3%, 28.4%, P = 0.06), respectively. In addition, it increased geometric mean neonatal intact-FGF23 concentrations by 21.6% (95% CI: 1.2%, 46.1%), increased geometric mean maternal hepcidin concentrations by 136.4% (95% CI: 86.1%, 200.3%), and decreased mean maternal 25-hydroxyvitamin D concentrations by 6.1 nmol/L (95% CI: -11.0, -1.2 nmol/L).

CONCLUSIONS

Analysis of this randomized trial confirms that iron supplementation can reverse elevated FGF23 production caused by iron deficiency in iron-deficient mothers and their neonates. Further investigations are warranted to assess to what extent iron supplementation can prevent FGF23-mediated hypophosphatemic rickets or osteomalacia.

Effects of Maternal Nutritional Supplements and Dietary Interventions on Placental Complications: An Umbrella Review, Meta-Analysis and Evidence Map

The placenta is a vital, multi-functional organ that acts as an interface between maternal and fetal circulation during pregnancy. Nutritional deficiencies during pregnancy alter placental development and function, leading to adverse pregnancy outcomes, such as pre-eclampsia, infants with small for gestational age and low birthweight, preterm birth, stillbirths and maternal mortality. Maternal nutritional supplementation may help to mitigate the risks, but the evidence base is difficult to navigate. The primary purpose of this umbrella review is to map the evidence on the effects of maternal nutritional supplements and dietary interventions on pregnancy outcomes related to placental disorders and maternal mortality. A systematic search was performed on seven electronic databases, the PROSPERO register and references lists of identified papers. The results were screened in a three-stage process based on title, abstract and full-text by two independent reviewers. Randomized controlled trial meta-analyses on the efficacy of maternal nutritional supplements or dietary interventions were included. There were 91 meta-analyses included, covering 23 types of supplements and three types of dietary interventions. We found evidence that supports supplementary vitamin D and/or calcium, omega-3, multiple micronutrients, lipid-based nutrients, and balanced protein energy in reducing the risks of adverse maternal and fetal health outcomes. However, these findings are limited by poor quality of evidence. Nutrient combinations show promise and support a paradigm shift to maternal dietary balance, rather than single micronutrient deficiencies, to improve maternal and fetal health. The review is registered at PROSPERO (CRD42020160887).

Maternal Compliance to Recommended Iron and Folic Acid Supplementation in Pregnancy, Sri Lanka: A Hospital-Based Cross-Sectional Study

Iron deficiency anaemia during pregnancy is a common public health problem that negatively affects maternal and newborn health. This study aims to identify the rate of maternal compliance with the recommended iron and folic acid (IFA) supplementation during pregnancy and to identify factors associated with maternal compliance and non-compliance. A hospital-based cross-sectional study was conducted among 703 women at 0-4 days postpartum. The prevalence of anaemia at the initial antenatal clinic (ANC) visit and at the third trimester were 20.8% and 44.9%, respectively. The rate of IFA supplementation compliance during pregnancy was 80.1%. Forgetfulness (66.9%) was the major reason for non-compliance, followed by side effects (15.7%). Maternal employment [OR (95%CI): 1.7 (1.00-2.89)], history of a low birth weight infant [OR (95%CI): 0.4 (0.19-0.9)] and history of anaemia [OR (95%CI): 0.4 (0.12-0.98] were significantly associated with maternal compliance with IFA supplementation. Only 26.6% of the participants adhered to dietary recommendations during the period when IFA supplements were provided. The rate of maternal compliance with IFA supplementation was high. However, the prevalence of maternal anaemia during pregnancy was also high, which was presumably due to poor dietary compliance despite high IFA supplementation compliance.

Comparison of different doses of daily iron supplementation for anemia prophylaxis in pregnancy: A systematic review

Different doses of iron are used for oral supplementation during pregnancy throughout the world. This objective of this review is to describe the effectiveness and side effect profile of different doses of oral iron supplementation for prophylaxis of anemia among pregnant women. Published literature was searched using keywords "iron," "pregnancy," and "supplementation" and related terms. Gray literature was searched in medical libraries including National Medical Library, Dr. B. B. Dikshit library, and library of ICMR. Intervention studies comparing different doses of oral iron given as prophylaxis for anemia during pregnancy, published till December 2017, were retrieved. Studies done only among anemic patients, and studies comparing oral iron with placebo were excluded. In total, 1588 studies were obtained and 11 of them met the objectives. In global studies, prophylactic dose of 30 mg and above is shown to maintain normal hemoglobin. Among the studies from India, prophylactic dose of 120 mg showed consistent results and 60 mg showed inconsistent results in increasing both hemoglobin and ferritin levels. No significant difference in side effects was reported up to 80 mg iron in global studies and the side effects were comparable with 60 to 240 mg doses in Indian studies. It was evident from the review that a state of clinical equipoise exists for the ideal dose of iron supplementation for the prevention of anemia in pregnancy in terms of efficacy and side effect profile. Robust clinical trial as well as technical consultation is required, especially in Indian setting to explore this question further.

Differences in the response to iron supplementation on oxidative stress, inflammation, and hematological parameters in nonanemic and anemic pregnant women

Background: Iron supplementation is widely recommended for all pregnant women, irrespective of their iron status. But providing excess iron to nonanemic pregnant women can result in iron overload, which may lead to oxidative stress and inflammation.Objectives: To assess the differential effect of iron supplementation on hematological parameters, oxidative stress, and inflammation in nonanemic and anemic pregnant women.Methods: Forty nonanemic and forty anemic pregnant women were recruited at 12 weeks of gestation. The study subjects were supplemented with iron (60 mg/day for nonanemic pregnant women and 120 mg/day for anemic pregnant women). Fasting state blood samples were collected at 12 and 28 weeks of gestation.Results: Malondialdehyde (MDA)/total antioxidant status (TAS) ratio (MDA/TAS) and high-sensitivity C-reactive protein (hsCRP) were significantly higher in anemic pregnant women before iron supplementation. Iron supplementation to the anemic pregnant women resulted in significant improvement in the hematological profile and ferritin levels. Further, the iron supplementation caused a significant reduction in hsCRP levels although the MDA/TAS ratio remained unaltered. Iron supplementation to nonanemic pregnant women resulted in a significant increase in the levels of MDA/TAS ratio and hsCRP, but there were no changes in hematological profile and serum ferritin levels.Conclusion: Prophylactic iron supplementation in nonanemic pregnant women increased oxidative stress and inflammation. However, in anemic pregnant women, iron supplementation was found to be beneficial as it improved hematological status and decreased inflammation without affecting oxidative stress.

Vitamin and Mineral Supplementation During Pregnancy on Maternal, Birth, Child Health and Development Outcomes in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

Almost two billion people are deficient in key vitamins and minerals, mostly women and children in low- and middle-income countries (LMICs). Deficiencies worsen during pregnancy due to increased energy and nutritional demands, causing adverse outcomes in mother and child, but could be mitigated by interventions like micronutrient supplementation. To our knowledge, this is the first systematic review that aimed to compile evidence from both efficacy and effectiveness trials, evaluating different supplementation interventions on maternal, birth, child health, and developmental outcomes. We evaluated randomized controlled trials and quasi-experimental studies published since 1995 in peer-reviewed and grey literature that assessed the effects of calcium, vitamin A, iron, vitamin D, and zinc supplementation compared to placebo/no treatment; iron-folic (IFA) supplementation compared to folic acid only; multiple micronutrient (MMN) supplementation compared to IFA; and lipid-based nutrient supplementation (LNS) compared to MMN supplementation. Seventy-two studies, which collectively involved 314 papers (451,723 women), were included. Meta-analyses showed improvement in several key birth outcomes, such as preterm birth, small-for-gestational age (SGA) and low birthweight with MMN supplementation, compared to IFA. MMN also improved child outcomes, including diarrhea incidence and retinol concentration, which are findings not previously reported. Across all comparisons, micronutrient supplementation had little to no effect on mortality (maternal, neonatal, perinatal, and infant) outcomes, which is consistent with other systematic reviews. IFA supplementation showed notable improvement in maternal anemia and the reduction in low birthweight, whereas LNS supplementation had no apparent effect on outcomes; further research that compares LNS and MMN supplementation could help understand differences with these commodities. For single micronutrient supplementation, improvements were noted in only a few outcomes, mainly pre-eclampsia/eclampsia (calcium), maternal anemia (iron), preterm births (vitamin D), and maternal serum zinc concentration (zinc). These findings highlight that micronutrient-specific supplementation should be tailored to specific groups or needs for maximum benefit. In addition, they further contribute to the ongoing discourse of choosing antenatal MMN over IFA as the standard of care in LMICs.

Prenatal Zinc and Vitamin A Reduce the Benefit of Iron on Maternal Hematologic and Micronutrient Status at Delivery in Tanzania

BACKGROUND

Zinc and vitamin A supplementation have both been shown to affect iron status, hemoglobin (Hb) concentration, and anemia in animal and human studies. However, evidence on their combined use in pregnancy, in the context of iron-folic acid (IFA) supplementation, remains limited.

OBJECTIVE

This study determined the effects of prenatal zinc, vitamin A, and iron supplementation on maternal hematologic and micronutrient status at delivery in Tanzania.

METHODS

We analyzed 2 large randomized controlled trials, using generalized estimating equations, and examined the effect of daily zinc (25 mg) and vitamin A (2500 IU) supplementation starting in the first trimester of pregnancy compared with placebo (n = 2500), and separately evaluated the safety and efficacy of daily iron (60 mg) supplementation among iron-replete pregnant women (n = 1500). Blood samples from baseline and delivery were tested for Hb, serum ferritin, soluble transferrin receptor, plasma zinc, and zinc protoporphyrin.

RESULTS

Zinc and vitamin A supplementation were associated with lower Hb concentrations at delivery of  -0.26 g/dL (95% CI: -0.50, -0.02 g/dL) and -0.25 g/dL (95% CI: -0.49, -0.01 g/dL), respectively. Vitamin A increased mean ferritin concentrations at delivery (14.3 μg/L, 95% CI: 1.84, 29.11 μg/L), but was associated with increased risk of severe anemia (RR: 1.41; 95% CI: 1.06, 1.88). Among women who were iron replete at baseline, iron supplementation reduced the risk of iron depletion at delivery by 47% (RR: 0.53; 95% CI: 0.43, 0.65). There was no effect of zinc or iron supplements on plasma zinc concentrations.

CONCLUSIONS

Our findings support existing WHO guidelines on prenatal iron, vitamin A, and zinc supplementation among pregnant women. In this setting, scaling uptake of prenatal iron supplements is warranted, but prenatal zinc and vitamin A supplementation did not benefit maternal hematologic status at delivery. In settings where vitamin A deficiency is endemic, the efficacy and safety of the WHO recommended prenatal vitamin A supplementation require further evaluation.

Hepcidin-guided screen-and-treat interventions against iron-deficiency anaemia in pregnancy: a randomised controlled trial in The Gambia

BACKGROUND

WHO recommends daily iron supplementation for pregnant women, but adherence is poor because of side-effects, effectiveness is low, and there are concerns about possible harm. The iron-regulatory hormone hepcidin can signal when an individual is ready-and-safe to receive iron. We tested whether a hepcidin-guided screen-and-treat approach to combat iron-deficiency anaemia could achieve equivalent efficacy to universal administration, but with lower exposure to iron.

METHODS

We did a three-arm, randomised, double-blind, non-inferiority trial in 19 rural communities in the Jarra West and Kiang East districts of The Gambia. Eligible participants were pregnant women aged 18-45 years at between 14 weeks and 22 weeks of gestation. We randomly allocated women to either WHO's recommended regimen (ie, a daily UN University, UNICEF, and WHO international multiple-micronutrient preparation [UNIMMAP] containing 60 mg iron), a 60 mg screen-and-treat approach (ie, daily UNIMMAP containing 60 mg iron for 7 days if weekly hepcidin was <2·5 μg/L or UNIMMAP without iron if hepcidin was ≥2·5 μg/L), or a 30 mg screen-and-treat approach (ie, daily UNIMMAP containing 30 mg iron for 7 days if weekly hepcidin was <2·5 μg/L or UNIMMAP without iron if hepcidin was ≥2·5 μg/L). We used a block design stratified by amount of haemoglobin at enrolment (above and below the median amount of haemoglobin on every enrolment day) and stage of gestation (14-18 weeks vs 19-22 weeks). Participants and investigators were unaware of the random allocation. The primary outcome was the amount of haemoglobin at day 84 and was measured as the difference in haemoglobin in each screen-and-treat group compared with WHO's recommended regimen; the non-inferiority margin was set at -5·0 g/L. The primary outcome was assessed in the per-protocol population, which comprised all women who completed the study. This trial is registered with the ISRCTN registry, number ISRCTN21955180.

FINDINGS

Between June 16, 2014, and March 3, 2016, 498 participants were randomised, of whom 167 were allocated to WHO's recommended regimen, 166 were allocated to the 60 mg per day screen-and-treat approach, and 165 were allocated to the 30 mg per day screen-and-treat approach. 78 participants were withdrawn or lost to follow-up during the study; thus, the per-protocol population comprised 140 women assigned to WHO's recommended regimen, 133 allocated to the 60 mg screen-and-treat approach, and 147 allocated to the 30 mg screen-and-treat approach. The screen-and-treat approaches did not exceed the non-inferiority margin. Compared with WHO's recommended regimen, the difference in the amount of haemoglobin at day 84 was -2·2 g/L (95% CI -4·6 to 0·1) with the 60 mg screen-and-treat approach and -2·7 g/L (-5·0 to -0·5) with the 30 mg screen-and-treat approach. Adherence, reported side-effects, and adverse events were similar between the three groups. The most frequent side-effect was stomachache, which was similar in the 60 mg screen-and-treat group (82 cases per 1906 person-weeks) and with WHO's recommended regimen (81 cases per 1974 person-weeks; effect 1·0, 95% CI 0·7 to 1·6); in the 30 mg screen-and-treat group the frequency of stomachache was slightly lower than with WHO's recommended regimen (58 cases per 2009 person-weeks; effect 0·7, 95% CI 0·5 to 1·1). No participants died during the study.

INTERPRETATION

The hepcidin-guided screen-and-treat approaches had no advantages over WHO's recommended regimen in terms of adherence, side-effects, or safety outcomes. Our results suggest that the current WHO policy for iron administration to pregnant women should remain unchanged while more effective approaches continue to be sought.

FUNDING

Bill & Melinda Gates Foundation and the UK Medical Research Council.

Maternal iron-deficiency is associated with premature birth and higher birth weight despite routine antenatal iron supplementation in an urban South African setting: The NuPED prospective study

Background

Recent studies are suggesting a U-shaped relationship between antenatal iron exposure and birth outcomes. Little is known about the iron status and associated birth outcomes of pregnant women in South Africa. Our aim was to assess iron status at early, mid- and late pregnancy, and to determine associations with gestational age and birth weight in women in Johannesburg, South Africa.

Methods

In this prospective study of 250 pregnant women, we measured haemoglobin, biomarkers of iron status and inflammation at <18, 22 and 36 weeks of gestation, plus birth weight and gestational age at delivery. Associations of anaemia and iron status with birth outcomes were determined using regression models adjusted for confounders.

Results

At enrolment, the prevalence of anaemia, iron depletion (ID) and iron deficiency erythropoiesis (IDE) was 29%, 15% and 15%, respectively, and increased significantly with pregnancy progression. Anaemia and ID at 22 weeks, as well as IDE at 36 weeks were associated with higher birth weight (β = 135.4; 95% CI: 4.8, 266.1 and β = 205.4; 95% CI: 45.6, 365.1 and β = 178.0; 95% CI: 47.3, 308.7, respectively). Women in the lowest ferritin quartile at 22 weeks gave birth to babies weighing 312 g (95% CI: 94.8, 528.8) more than those in the highest quartile. In contrast, IDE at 22 weeks was associated with a higher risk for premature birth (OR: 3.57, 95% CI: 1.24, 10.34) and women in lower haemoglobin quartiles at <18 weeks had a shorter gestation by 7 days (β = -6.9, 95% CI: -13.3, -0.6) compared to those in the highest quartile.

Conclusion

Anaemia, ID and IDE prevalence increased during pregnancy despite routine iron supplementation. ID and anaemia at mid-pregnancy were associated with higher birth weight, while IDE was associated with premature birth. These results suggest that current antenatal screening and supplementation practices in South Africa need to be revisited.

National Iron Plus Initiative: Current status & future strategy

Anaemia is a severe public health problem amongst all vulnerable age groups in India. The National Nutritional Anaemia Prophylaxis Programme initiated in 1970, was revised and expanded to include beneficiaries from all age groups namely children aged 6-59 months, 5-10 yr, adolescents aged 10-19 yr, pregnant and lactating women and women in reproductive age group under the National Iron Plus Initiative (NIPI) programme in 2011. The dose of iron, frequency and duration of iron supplementation and roles and responsibilities of the functionaries were described. At present, the coverage of beneficiaries with iron and folic acid has been poor at the national level. The prevalence of anaemia has continued to remain high during the last 60 years, and there has been no significant change in the scenario due to various reasons. The constraints in implementation and measures to improve the NIPI programme are discussed in the current article.

Antenatal iron supplementation and birth weight in conditions of high exposure to infectious diseases

BACKGROUND

A recent cohort study among Papua New Guinean women surprisingly showed iron deficiency during pregnancy to be associated with increased birth weight. These findings seemingly contradict previous trial evidence that iron supplementation leads to increased birth weight, particularly in iron-deficient women, and hence require explanation.

MAIN TEXT

We have re-analysed data from a previous trial in Kenya and demonstrated that, because women who were initially iron deficient respond better to iron supplementation, they show an increase in birthweight. There is evidence that this benefit is decreased in iron-replete women, possibly due to the adverse effects of haemoconcentration that can impair oxygen and nutrient transfer across the placenta. The Papua New Guinean results might be explained by a similar differential response to the iron supplements that they all received.

CONCLUSIONS

Antenatal iron supplementation should ideally be administered in conjunction with measures to prevent, diagnose and treat malaria given the propensity of pathogenic microorganisms to proliferate in iron-supplemented individuals. However, even where services to prevent and treat malaria are poor, current evidence supports the conclusion that the benefits of universal iron supplementation outweigh its risks. Please see related article: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-018-1146-z. Please see related article: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-019-1376-8.

Prevalence of intestinal parasitic infection and its association with anemia among pregnant women in Wondo Genet district, Southern Ethiopia: a cross-sectional study

BACKGROUND

Previous studies reported contradicting findings about the association between intestinal parasitosis and maternal anemia. In this study we aimed to determine the prevalence of intestinal parasitic infection and its association with anemia among pregnant women in Wondo Genet district, Southern Ethiopia.

METHODS

This facility-based cross-sectional study was conducted in June and July 2018. Pregnant women (n = 352) were randomly drawn from five health centers using antenatal care follow-up lists. Trained data collectors administered the questionnaire. Capillary blood was collected and analyzed for hemoglobin using the HemoCue method. Stool sample was collected following standard procedure and analyzed for the presence and types of intestinal parasites using direct microscopy with Formalin-ether concentration technique. Association between intestinal parasitosis and anemia was measured using multivariable binary logistic regression analysis. The outputs are presented using adjusted odds ratio (AOR) with 95% confidence intervals (CI).

RESULTS

The overall prevalence of intestinal parasitic infection was 38.7% (95% CI: 33.6-43.8%). One-tenth (9.7%) of the pregnant women were infected with polyparasites. Ascaris lumbricoides was the predominant infection encountered in 24.9% of the women. The other infections identified were: hookworms (11.2%), Giardia lamblia (5.4%), Entamoeba histolytica (3.4%), Trichuris trichiura (2.9%) and Schistosoma mansoni (2.3%). The mean (± standard deviation) hemoglobin concentration was 12.3 (±1.9) g/dl and 31.5% (95% CI: 26.6-36.4%) women were anemic (hemoglobin < 11 g/dl). The prevalence of anemia among women infected with intestinal parasite (55.6%) was substantially higher than the prevalence in their counterparts (16.4%) (p <  0.001). In a multivariable model adjusted for multiple potential confounders including socio-economic status indicators, the odds of anemia were six times increased (AOR = 6.14, 95% CI: 2.04-18.45) among those affected by at least one intestinal parasite.

CONCLUSION

Strengthening the existing water, sanitation and hygiene programs and routine deworming of pregnant mothers may help to reduce the burden of both intestinal parasitic infection and anemia in pregnant women.

Interventions to prevent iron deficiency during the first 1000 days in low-income and middle-income countries: recent advances and challenges

PURPOSE OF REVIEW

Iron deficiency remains highly prevalent in women and young children in low-income and middle-income countries. To prevent the potentially life-long consequences of iron deficiency when occurring during early life, the WHO recommends iron supplementation of pregnant women and young children. However, increasing evidence of limited efficacy and risk of current iron intervention strategies are cause of concern. This review aims to highlight recent advances and challenges of established and novel intervention strategies for the prevention of iron deficiency during the first 1000 days in low-income and middle-income countries.

RECENT FINDINGS

Recent meta-analyses and trials challenged the WHO's current recommendation to provide iron-folic acid rather than multiple micronutrient supplements during routine antenatal care. Furthermore, several studies explored optimal windows for iron supplementation, such as prior to conception. Studies are demonstrating that infectious and noninfectious inflammation is compromising the efficacy of iron interventions in vulnerable groups. Therefore, strategies addressing iron deficiency should focus on targeting infection and inflammation while simultaneously providing additional iron. Furthermore, both iron deficiency and iron supplementation may promote an unfavourable gut microbiota. Recent trials in infants indicate that the provision of a prebiotic together with iron may alleviate the adverse effects of iron on the gut microbiome and gut inflammation, and may even enhance iron absorption.

SUMMARY

Recent studies highlight the need for and potential of novel intervention strategies that increase the efficacy and limit the potential harm of universal iron supplementation.

Safety of Oral and Intravenous Iron

As the adverse effects of iron deficiency are better recognized, the use of oral and intravenous iron has increased dramatically. Oral iron is often poorly tolerated, with up to 70% or more of patients noting gastrointestinal issues; this may affect adherence to therapy. In addition, many patients will not respond to oral iron due to their underlying illness. Intravenous iron is being used more frequently to replete iron stores. True anaphylaxis is very rare, but complement-mediated infusion reactions may be seen in up to 1 in every 200 patients. Previous concerns about intravenous iron increasing the risk of infection or cardiovascular disease are unfounded.

Iron Status of Kenyan Pregnant Women after Adjusting for Inflammation Using BRINDA Regression Analysis and Other Correction Methods

Serum ferritin concentration is the preferred biomarker to assess population iron status in the absence of inflammation. Interpretation of this biomarker is complicated in populations with a high burden of infection, however, because inflammation increases serum ferritin concentration independently of iron status. We aimed to compare estimates of iron status of Kenyan pregnant women, with circulating ferritin concentrations adjusted for inflammation using newly proposed methods by the BRINDA project, or using previously proposed adjustment methods. We re-analyzed data from pregnant Kenyan women living in a rural area where malaria is highly endemic (n = 470) or in an urban area (n = 402). As proposed by the BRINDA group, we adjusted individual ferritin concentration by internal regression for circulating concentrations of C-reactive protein (CRP) and α₁-acid glycoprotein (AGP). Other adjustment methods comprised: (a) arithmetic correction factors based on CRP or AGP; (b) exclusion of subjects with inflammation (CRP >5 mg/L or AGP >1 g/L); and (c) higher ferritin cut-off value (<30 μg/L). We additionally adjusted for Plasmodium infection as appropriate. Lastly, we assessed iron status without adjustment for inflammation. All correction methods increased prevalence of iron deficiency compared to the unadjusted estimates. This increase was more pronounced with the internal regression correction method. The iron deficiency prevalence estimate increased from 53% to 87% in rural Kisumu study and from 30% to 41% in the urban Nairobi study after adjusting for inflammation (CRP and AGP) using the BRINDA internal regression method. When we corrected for both inflammation and Plasmodium infection using the regression correction, it resulted in lower prevalence estimates compared to uninfected women. Application of linear regression methods to adjust circulating ferritin concentration for inflammation leads to markedly decreased point estimates for ferritin concentration and increased estimates for the prevalence of iron deficiency in pregnancy.

Biochemical and hematological changes among anemic and non-anemic pregnant women attending antenatal clinic at the Bolgatanga regional hospital, Ghana

BACKGROUND

Anemia in pregnancy may not only be associated with maternal morbidity and mortality but can also be detrimental to the fetus. A definitive diagnosis of anemia is a pre-requisite to unravelling possible cause(s), to allow appropriate treatment intervention. It is hypothesised that measured hemoglobin (HGB), complemented by biochemical and other hematological parameters would enhance anemia diagnosis.

METHODS

This was a cross-sectional study among 400 pregnant women comprising 253 anemic and 147 non-anemic pregnant women, attending an antenatal clinic at Bolgatanga Regional Hospital, Ghana. Venous blood was collected and hemoglobin genotype, complete blood count and biochemical parameters [ferritin, iron, total iron binding capacity (TIBC), transferrin saturation (TfS), C-reactive protein (CRP) and bilirubin] were determined. Thick blood films were prepared for malaria parasitemia, while early morning stool and midstream urine samples were examined for enteric and urogenital parasites, respectively.

RESULTS

There were significantly reduced levels of HGB (p < 0.0001), HCT (p < 0.0001), MCV (p < 0.0001), iron (0.0273), ferritin (p = 0.018) and transferrin saturation (0.0391) and increased WBC (p = 0.006), RDW (p = 0.0480), TIBC (p = 0.0438) and positivity of CRP in anemic, compared to non-anemic pregnant women. Anemic women were associated with increased proportion of hemoglobinopathies (AS, SS and SC), Plasmodium falciparum, Schistosoma hematobium and intestinal parasite infections.

CONCLUSION

Anemic pregnant women are associated with a significant derangement in hematological and iron indices that implicate iron deficiency. This was influenced by hemoglobinopathies and parasitic infections.

Cooperative Metabolic Adaptations in the Host Can Favor Asymptomatic Infection and Select for Attenuated Virulence in an Enteric Pathogen

Pathogen virulence exists on a continuum. The strategies that drive symptomatic or asymptomatic infections remain largely unknown. We took advantage of the concept of lethal dose 50 (LD50) to ask which component of individual non-genetic variation between hosts defines whether they survive or succumb to infection. Using the enteric pathogen Citrobacter, we found no difference in pathogen burdens between healthy and symptomatic populations. Iron metabolism-related genes were induced in asymptomatic hosts compared to symptomatic or naive mice. Dietary iron conferred complete protection without influencing pathogen burdens, even at 1000× the lethal dose of Citrobacter. Dietary iron induced insulin resistance, increasing glucose levels in the intestine that were necessary and sufficient to suppress pathogen virulence. A short course of dietary iron drove the selection of attenuated Citrobacter strains that can transmit and asymptomatically colonize naive hosts, demonstrating that environmental factors and cooperative metabolic strategies can drive conversion of pathogens toward commensalism.

Iron Nutriture of the Fetus, Neonate, Infant, and Child

Iron is a key nutrient and is essential for the developing fetus, neonate, infant, and child. Iron requirements are high during early stages of life because it is critically important for the production of new red blood cells and muscle cells as well as brain development. Neonates, infants, and children obtain iron from dietary sources including breast milk (lactoferrin) and heme- and non-heme-containing foods. Iron deficiency (ID) is the most common micronutrient deficiency in children and pregnant women worldwide. ID and iron deficiency anemia (IDA) can affect growth and energy levels as well as motor and cognitive performance in the developing child. The fetus is completely dependent on maternal iron crossing through the placenta and, although it is generally well protected against deficiency at birth, ID in mothers can increase the risk of ID and IDA in their children as early as 4 months. This review will discuss the uses of iron, iron requirements, and the sources of iron from conception through childhood. In addition, it will describe the prevalence and clinical manifestations of ID and IDA in children and discuss recommendations for iron supplementation of children and pregnant women.

Maternal and neonatal outcomes related to iron supplementation or iron status: a summary of meta-analyses

BACKGROUND

Iron deficiency is the most abundant nutritional deficiency in the world and is discussed to be associated with adverse pregnancy outcomes. The objective of this review was to perform an umbrella summary of meta-analyses to evaluate the effects and associations of iron supplementation or iron status on maternal and birth/neonatal outcomes.

METHODS

A literature search was conducted on PubMed and Scopus by two reviewers without temporal restriction. Systematic reviews and meta-analyses of studies evaluating (1) the effects of multimicronutrient compared to iron + folic acid supplementations on maternal and birth/neonatal outcomes (2), the association of dietary iron intake or hemoglobin or ferritin status regarding the risk for maternal (gestational diabetes mellitus (GDM)) and birth/neonatal outcomes, and (3) the effects of iron supplementation on pregnancy and birth/neonatal outcomes, were included in this review.

RESULTS

Overall, 16 meta-analyses were included. Multimicronutrient supplements had significant risk reducing effects on low birth weight and small for gestational age compared to iron/folic acid supplements as controls. Furthermore, most of the meta-analyses showed that higher levels of hemoglobin or ferritin increased the risk for GDM. On the other hand, maternal anemia (low hemoglobin levels) was associated with adverse birth/neonatal outcomes. Finally, iron supplementation reduced the risk of iron deficiency and iron deficiency anemia and had some risk reducing effects on low birth weight newborns.

CONCLUSIONS

Our summary of meta-analyses showed that multimicronutrient supplementation had beneficial effects on some neonatal outcomes. Furthermore, higher ferritin levels seem to increase the risk for GDM whereas maternal anemia was associated with adverse birth/neonatal outcomes.