Iron Supplementation during Pregnancy and Infancy: Uncertainties and Implications for Research and Policy

International expert consensus on micronutrient supplement use during the early life course

BACKGROUND

Growing evidence demonstrates that maternal nutrition is crucial for the health of the mother-to-be, and early life course of the offspring. However, for most micronutrients, guidelines are inconsistent. This Delphi study aimed to investigate the level of expert consensus on maternal nutrition and micronutrient needs during preconception, pregnancy and lactation.

METHODS

We conducted a two-round web-based Delphi survey on various topics including general approaches to diet and supplement use, and existing guidelines. For the periods of preconception, pregnancy and lactation, questions focused on the importance and strength of evidence for supplement use with the following micronutrients for low- and high-risk populations: folic acid, choline, iodine, magnesium, calcium, iron, selenium, docosahexaenoic acid (DHA), and vitamins B1, B2, B6, B12, D and K.

RESULTS

Thirty-five experts participated in the panel, who were healthcare professionals (HCPs), researchers and joint HCP-researchers with expertise in nutrition, gynaecology and/or obstetrics. Panellists reached consensus on the importance of diet and dietary supplement use during pregnancy and agreed on the lack of clarity and consistency in current guidelines, and the need for education in these areas for HCPs, pregnant people and the general population. For general low-risk populations, there was consensus on the importance of supplement use with iron and vitamin D from preconception through lactation, with folic acid and iodine from preconception through the second and third trimesters, respectively, with DHA from the first trimester through lactation and with calcium during lactation. Panellists agreed that the evidence for supplement use with each of these micronutrients during these phases to improve outcomes and/or foetal development is strong, except for vitamin D (preconception), DHA (first trimester), and iron (both periods). There was also consensus that supplement use advice should be tailored for people following vegan/vegetarian diets, restricted diets due to food intolerances, obesity, polycystic ovary syndrome, diabetes mellitus, and previous nutrition-related pregnancy complications.

CONCLUSION

The findings revealed robust consensus on various aspects of maternal nutrition, including the need for education, the lack of consistency in current guidelines on supplement use, the importance of supplement use across specific phases of pregnancy and the at-risk groups requiring tailored approaches.

Arsenic induces ferroptosis in HTR-8/SVneo cells and placental damage

Placenta ferroptosis has been proven to be associated with a variety of adverse pregnancy outcomes. Arsenic, a conventional metal noxious substance, has garnered considerable attention due to traversing the placental barrier. How arsenic induces placental ferroptosis and reproductive developmental toxicities remains largely unknown. Herein, we investigated the impact of sodium arsenite (As (III)) on iron homeostasis in the placenta through both in vivo and in vitro experiments by using HTR-8/SVneo cells and ICR pregnant mice. As (III) up-regulated the expression of genes or proteins associated with iron uptake (TFRC, DMT1), iron storage (FTH, FTL), ferritin autophagy (NCOA4), and heme degradation (HO-1), and induced cell iron overload. Additionally, accumulation of the lipid hydroperoxide malondialdehyde within cells was triggered by As (III) through inhibition of the Nrf2/GPX4 signal pathway, which resulted in cellular ferroptosis. Fer-1 effectively alleviated the suppression of GPX4 induced by As (III), reduced the accumulation of intracellular lipid peroxidation product MDA, and mitigated cellular ferroptosis. As (III) affected the iron homeostasis, as evidenced by the abnormal iron accumulation in the placenta. Placental structural abnormalities and hemorrhage may be the reason for As (III) causing placental injury and subsequent poor pregnancy outcomes. This study provides new insights into understanding the mechanisms by which As (III) produces placental damage and possible fetal developmental toxicity.

Association between iron deficiency anemia and severe maternal morbidity: A retrospective cohort study

PURPOSE

We examined the association between iron deficiency anemia (IDA) and severe maternal morbidity (SMM) during delivery and up to 1-year postpartum.

METHODS

In a retrospective cohort study across 3 states, we computed adjusted relative risks (aRR) for SMM comparing individuals with IDA versus those without, using modified Poisson regression models.

RESULTS

Among 2459,106 individuals, 10.3 % (n = 252,240) had IDA. Individuals with IDA experienced higher rates of blood transfusion and non-transfusion SMM (329 and 122 per 10,000 deliveries, respectively) than those without IDA (33 and 46 per 10,000 deliveries, respectively). The risk of blood transfusion (aRR: 8.2; 95 % CI 7.9-8.5) and non-transfusion SMM (aRR: 1.9; 95 % CI: 1.8-2.0) were higher among individuals with IDA. The attributable risk per 10,000 deliveries due to IDA for blood transfusion and non-transfusion SMM during delivery were 29.5 (95 % CI: 28.9-30.0) and 5.7 (95 % CI: 5.3-6.2), respectively. Within 1-year postpartum, the relative risk of non-transfusion SMM (aRR:1.3; 95 % CI: 1.2-1.3) was 30 % higher among individuals with IDA.

CONCLUSION

IDA is associated with increased SMM risk. Addressing IDA in pregnant individuals may reduce SMM rates.

Early life stress and iron metabolism in developmental psychoneuroimmunology

An estimated 250 million children face adverse health outcomes from early life exposure to severe or chronic social, economic, and nutritional adversity, highlighting/emphasizing the pressing concern about the link between ELS and long-term implications on mental and physical health. There is significant overlap between populations experiencing high levels of chronic stress and those experiencing iron deficiency, spotlighting the potential role of iron as a key mediator in this association. Iron, an essential micronutrient for brain development and immune function, is often depleted in stress conditions. Iron deficiency among the most common nutrient deficiencies in the world. Fetal and infant iron status may thus serve as a crucial intermediary between early chronic psychological stress and subsequent immune system changes to impact neurodevelopment. The review presents a hypothesized pathway between early life stress (ELS), iron deficiency, and neurodevelopment through the hypothalamic-pituitary-adrenocortical (HPA) axis and the IL-6-hepcidin axis. This hypothesis is derived from (1) evidence that stress impacts iron status (2) long-term neurodevelopmental outcomes that are shared by ELS and iron deficiency exposure, and (3) possible mechanisms for how iron may mediate the relation between ELS and iron deficiency through alterations in the developing immune system. The article concludes by proposing future research directions, emphasizing the need for rigorous studies to elucidate how stress and iron metabolism interact to modify the developing immune system. Understanding these mechanisms could open new avenues for improving human health and neurodevelopment for women and children globally, making it a timely and vital area of study in psychoneuroimmunology research.

Association between anemia in pregnancy with low birth weight and preterm birth in Ethiopia: A systematic review and meta-analysis

BACKGROUND

Anemia in pregnancy has been associated with a number of adverse birth outcomes, such as low birth weight (LBW) or preterm birth (PTB). However, the evidence from primary studies on anemia in pregnancy with LBW and PTB is contentious. Moreover, a systematic review and meta-analysis to summarize these findings have not been conducted for Ethiopia. This study aimed to synthesize the best available evidence and quantify the strength and direction of the association of anemia in Ethiopia.

METHODS

This review examined women with singleton pregnancies with low birth weight (LBW) and preterm birth (PTB). We retrieved studies from PubMed, Wiley, Cochrane databases, and Google Scholar from inception to February 2, 2024. The World Health Organization (WHO) defines anemia in pregnancy as a low blood haemoglobin (Hgb) concentration below 11 g/dl or a hematocrit level of < 33%. When the newborn's weight was below 2500 g, LBW was considered. Preterm birth refers to the birth of a baby before 37 completed weeks of gestation. Meta-analysis was conducted using fixed and random effects models. The degree of heterogeneity, publication bias, and quality of the evidence of studies was assessed.

RESULTS

There were 35 and 8 studies, with 14,319 and 3,265 respondents included in the meta-analysis for LBW and PTB, respectively. Neonates born to women who had normal Hgb levels were less likely to be LBW [pooled odds ratio (POR) = 0.22, 95% CI: (0.17, 0.28); I2 = 80%] (low-quality evidence). Neonates born to women with normal Hgb levels had a lower risk of PTB [POR = 0.22, 95% CI: 0.18, 0.28; I2 = 19%] (very low-quality evidence). The effect size estimate remained significant after sub-group analysis based on study design and province, except in two retrospective cohort studies for LBW.

CONCLUSION

The findings suggest major implications for strengthening the implementation of nutrition policies to prevent anemia during pregnancy in Ethiopia. Further research is warranted to assess interventions that are effective in combating maternal anemia to reduce rates of LBW and PTB.

Iron status and anemia in a representative sample of US pregnant women is not associated with pre-pregnancy BMI: Results from the NHANES (1999-2010) study

Iron deficiency in pregnancy is related to many poor health outcomes, including anemia and low birth weight. A small number of previous studies have identified maternal body mass index (BMI) as a potential risk factor for poor iron status. Our objective was to examine the association between pre-pregnancy BMI, iron status, and anemia in a nationally representative sample of US adult women. We used data from the National Health and Nutrition Examination Survey (NHANES; 1999-2010) for pregnant women ages 18-49 years (n = 1156). BMI (kg/m2) was calculated using pre-pregnancy weight (self-reported) and height (measured at examination). Iron deficiency (ID) was defined as total body iron (calculated from serum ferritin and transferrin receptor using Cook's equation) < 0 mg/kg and anemia as hemoglobin < 11 g/dL. Associations were examined using weighted linear and Poisson regression models, adjusted for confounders (age, race/ethnicity, education, and trimester). Approximately 14% of pregnant women had ID and 8% had anemia in this sample. Ferritin and total body iron trended slightly lower (p = 0.12, p = 0.14) in women with pre-pregnancy BMI in the normal and overweight categories compared to the underweight and obese categories; hemoglobin concentrations were similar across BMI groups (p = 0.76). There were no differences in the prevalence of ID or anemia in women with pre-pregnancy overweight and obesity (ID: overweight, adjusted prevalence ratio (PR) = 1.27, 95%CI: 0.89-1.82; obesity, PR = 0.75, 95%CI: 0.39-1.45; anemia: overweight, PR = 1.08, 95%CI: 0.53-2.19; obesity, PR = 0.99, 95%CI: 0.49-2.01) compared to women with a normal BMI. Findings from these US nationally representative data indicate that total body iron, serum hemoglobin, ID, and anemia in pregnancy do not differ by pre-pregnancy BMI. Since ID and anemia during pregnancy remain significant public health concerns, NHANES should consider measuring current iron status in upcoming cycles.

Dietary diversity and iron deficiency anemia among a cohort of singleton pregnancies: a cross-sectional study

BACKGROUND

Iron deficiency anemia (IDA) is considered one of the most common medical disorders observed during pregnancy. In low- and middle-income countries (LMICs), anemia and micronutrients deficiencies among pregnant women are associated with low consumption of animal products, monotonous starchy-diets, and seasonal consumption of vegetables and fruits.

METHODS

A cross-sectional study was conducted with 198 pregnant mothers aged between 19-45 years who visited the antenatal care clinics in Northern Jordan to document the prevalence of IDA and to describe the associations between dietary diversity, diet quality scores and oral iron supplementation with the pregnant women iron status. Participants were stratified into three groups by gestational age (n = 66 women per group). Gestational age, blood parameters, minimum dietary diversity score (MDD-W), and prime diet quality score for healthy (PDQSHF) and unhealthy foods (PDQSUF) were assessed using 24- hour dietary recall.

RESULTS

Prevalence of mild to moderate anemia was 27.8% among pregnant women. Third-trimester pregnant women were most affected. 52.5% have depleted iron stores (ferritin < 15 ng/ml), of them 30.8% have iron deficiency, and 21.7% have IDA. The (M ± SD) of the MDD-W, PDQSHF, and PDQSUF were 4.8 ± 1.6, 12.8 ± 3.9, and 7.2 ± 2.8 respectively. 52.5% achieved the MDD-W, 68% consumed < 4 servings/week of healthy food groups, and 50% consumed > 4 servings/week of unhealthy food groups. Mothers with higher MDD-W and PDQS had higher Hb and serum concentrations. Those taking iron supplements had significantly (p = 0.001) higher means of Hb, serum ferritin, and gestational weight gain. Significant differences were also found between PDQSHF, PDQSUF and the first and third trimester.

CONCLUSIONS

Mild to moderate IDA is prevalent among pregnant mothers, especially in the third trimester. However, the prevalence of IDA among Jordanian pregnant women is lower than the global average. A high-quality, diverse diet, combined with oral iron supplementation and food fortification with iron, will help improve iron status, prevent anemia, and reduce its prevalence.

Retrospective audit compares screening and treatment of pregnancy-related anaemia in regional New South Wales with Australian guidelines

BACKGROUND

Anaemia during pregnancy is common worldwide. In Australia, approximately 17% of non-pregnant women of reproductive age have anaemia, increasing to a rate of 25% in pregnant women. This study sought to determine the rate of screening for anaemia in pregnancy in regional New South Wales, and to determine whether screening and treatment protocols followed the recommended guidelines.

METHODS

This retrospective study reviewed antenatal and postnatal (48 h) data of women (n = 150) who had a live birth at Bathurst Hospital between 01/01/2020 and 30/04/2020. Demographic data, risk factors for anaemia in pregnancy, antenatal bloods, treatments provided in trimesters one (T1), two (T2) and three (T3), and postpartum complications were recorded. These were compared to the Australian Red Cross Guidelines (ARCG) using descriptive statistics.

RESULTS

Of the women with screening data available (n = 103), they were mostly aged 20-35yrs (79.6%), 23.3% were obese, 97.1% were iron deficient, 17% were anaemic and only a few (5.3%) completed the full pregnancy screening as recommended by the ARCG while a majority completed only partial screenings specifically Hb levels in T1 (56.7%), T2 (44.7%) and T3 (36.6%). Compliance to oral iron was largely undocumented, but constipation was a common side effect among the women. IV iron was administered in 14.0% of women, approximately 1.75x higher than the recommended rate.

CONCLUSIONS

This study provided useful information about compliance to screening and treatment guidelines for anaemia in pregnancy. We identified the need for improved documentation and communication between various health providers to ensure adequate antenatal care to prevent maternal complications during pregnancy. This will improve patient care and encourage further developments in maternal care, bridging the rural health gap.

Epigenetic modifications in the ferroptosis pathway in cord blood cells from newborns of smoking mothers and their influence on fetal growth

Maternal smoking during pregnancy increases oxidative stress and decreases antioxidant capacity in newborns. Uncontrolled oxidative stress plays a role in fetal development disorders and in adverse perinatal outcomes. In order to identify molecular pathways involved in low fetal growth, epigenetic modifications in newborns of smoking and non-smoking mothers were examined. Low birth weight newborns of mothers who smoked more than 10 cigarettes per day during the first trimester of pregnancy and normal birth weight newborns of mothers who did not smoke during pregnancy were included in the study. DNA was extracted from umbilical cord blood of term newborns. 125 differentially methylated regions were identified by MeDIP-Seq. Functional analysis revealed several pathways, such as ferroptosis, that were enriched in differentially methylated genes after prenatal smoke exposure. GPX4 and PCBP1 were found to be hypermethylated and associated with low fetal growth. These epigenetic modifications in ferroptosis pathway genes in newborns of smoking mothers can potentially contribute to intrauterine growth restriction through the induction of cell death via lipid peroxidation of cell membranes. The identification of epigenetic modifications in the ferroptosis pathway sheds light on the potential mechanisms underlying the pathophysiology of low birth weight in infants born to smoking mothers.

Unraveling the Role of Maternal Serum Ferritin Levels in Preterm Delivery: A Comprehensive Review

Preterm delivery remains a critical global health concern, with numerous adverse consequences for both neonate and healthcare systems. Understanding the relationship between maternal ferritin levels, as a marker of iron status, and the risk of preterm birth is the focal point of this comprehensive review. We provide insights into the multifaceted nature of this connection, highlighting factors that influence maternal ferritin levels, including dietary intake, genetic and physiological variations, comorbidities, and iron supplementation. While evidence suggests an association between low maternal ferritin levels and preterm birth, causality remains elusive, necessitating further research with robust study designs. The potential mechanisms linking maternal iron status to preterm birth, such as inflammation, infection, and oxidative stress, are explored, underscoring the need for in-depth investigations. This comprehensive review emphasizes the clinical importance of assessing and monitoring maternal ferritin levels in prenatal care and advocates for public health initiatives to raise awareness and provide targeted interventions, particularly in high-risk populations. As we strive to address these unanswered questions and embark on innovative research directions, the aim is to ultimately enhance our understanding of the complex relationship between maternal iron status and preterm birth, leading to improved maternal and child health outcomes.

Modified Shoutai Pill inhibited ferroptosis to alleviate recurrent pregnancy loss

ETHNOPHARMACOLOGICAL RELEVANCE

Modified Shoutai Pill, also called Jianwei Shoutai Pill (JSP), is a traditional Chinese medicine prescription that has been used as an effective agent for the treatment of miscarriage.

AIM OF THE STUDY

To explore the potential molecular mechanism of JSP against recurrent pregnancy loss (RPL).

MATERIALS AND METHODS

In vivo, CBA/J mated DBA/2 mice were used to conduct RPL model, while CBA/J mated BALB/c mice were seen as the control group. Mice were orally administered with JSP, Fer-1 (a ferroptosis inhibitor) or distilled water from day 0.5-12.5 of gestation (GD 0.5-12.5). Pregnancy outcomes were analyzed and ferroptosis related indexes of the whole implantation sites were measured on GD 12.5. In vitro, human trophoblast cell line HTR-8/SVneo was cultured and treated with RAS-selective lethal small molecule 3 (RSL3) (a ferroptosis agonist) or different concentrations of JSP. Then, ferroptosis related indexes were tested to analyze whether JSP could inhibit ferroptosis in HTR-8/SVneo cells.

RESULTS

In vivo consequences demonstrated that JSP or Fer-1 alleviated pregnancy outcomes including lower resorption rate and abortion rate. In addition, excessive iron accumulation and MDA level were inhibited, while GSH and GPX content were raised under JSP or Fer-1 exposure. Also, JSP or Fer-1 enhanced protein expressions of GPX4 and SLC7A11 which suppress ferroptosis, and lightened protein expression of ACSL4 which boosts ferroptosis. In vitro, JSP rescued HTR-8/SVneo cell death and migration ability that were injured by RSL3. Furthermore, JSP inhibited RSL3-induced intracellular reactive oxygen species (ROS), lipid ROS and iron deposition.

CONCLUSIONS

Collectively, our findings illustrated that the mechanism of JSP in treating RPL might be related to inhibiting ferroptosis, which provided a novel insight into the application of JSP in RPL intervention.

Iron, folic acid, and vitamin D supplementation during pregnancy: Did pregnant Chilean women meet the recommendations during the COVID pandemic?

BACKGROUND

Antenatal micronutrient supplementation has been defined as a priority for Low-and Middle-income Countries (LMICs). However, it is also relevant to assess its performance in middle-high income countries, such as Chile, particularly given the post-pandemic food insecurity context.

AIM

To assess the use (frequency and doses) of daily recommended supplementation (iron (15-30 mg), folic acid (FA) (400-800 μg/day), and vitamin (VD) (400 IU)) in a sample of Chilean pregnant women.

METHODS

In 1, 507 pregnant women selected from public health care registries of the Southeast area of Santiago-Chile, we collected maternal, supplement use, sociodemographic, and nutritional information at the first (<15 weeks), second (24-28 weeks), and third trimesters (32-36 weeks) of gestation by using a researcher administer online questionnaire.

RESULTS

The median (IQR) age of women was 29 (25-33) years. Pre-conceptional supplementation was rare (24%), but it reached >93% in the first trimester; thereafter supplement use decreased to 79% in the second and 84% in the third trimesters, particularly in women with lower income (p<0.05), lower education (p<0.05), and with excess weight (p<0.05). Use of iron supplements in the first trimester was rare (<21%) as well as the use of VD supplements across pregnancy (<31%). Most FA (70%) and iron (80%) supplement users, exceeded the recommended daily dose while ~40% of VD users took less than the recommended dose.

CONCLUSIONS

In this sample of Chilean women, timely initiation of FA, iron, and VD supplementation was low and doses were not aligned with the recommendations. Strengthening adherence and quality of micronutrient supplementation programs delivered through public primary care could benefit particularly the most vulnerable women.

Impact of ferroptosis on preeclampsia: A review

Preeclampsia (PE) is usually associated with the accumulation of reactive oxygen species (ROS) resulting from heightened oxidative stress (OS). Ferroptosis is a unique type of lipid peroxidation-induced iron-dependent cell death distinct from traditional apoptosis, necroptosis, and pyroptosis and most likely contributes considerable to PE pathogenesis. At approximately 10-12 weeks of gestation, trophoblasts create an environment rich in oxygen and iron. In patients with PE, ferroptosis-related genes such as HIF1 and MAPK8 are downregulated, whereas PLIN2 is upregulated. Furthermore, miR-30b-5p overexpression inhibits solute carrier family 11 member 2, resulting in a decrease in glutathione levels and an increase in the labile iron pool. At the maternal-fetal interface, physiological hypoxia/reperfusion and excessive iron result in lipid peroxidation and ROS production. Owing to the high expression of Fpn and polyunsaturated fatty acid-containing phospholipid-related enzymes, including acyl-CoA synthetase long-chain family member 4, lysophosphatidylcholine acyl-transferase 3, and spermidine/spermine N1-acetyltransferase 1, trophoblasts become more susceptible to OS and ROS damage. In stage 1, the injured trophoblasts exhibit poor invasion and incomplete uterine spiral artery remodeling caused by ferroptosis, leading to placental ischemia and hypoxia. Subsequently, ferroptosis marked by OS occurs in stage 2, eventually causing PE. We aimed to explore the new therapeutic target of PE through OS in ferroptosis.

Importance of Maternal Iron Status on the Improvement of Cognitive Function in Children After Prenatal Iron Supplementation

INTRODUCTION

The effectiveness of prenatal iron supplementation improves maternal hematological outcomes, but little research has focused on child outcomes. The objective of this study was to assess whether prenatal iron supplementation adjusted to maternal needs improves children's cognitive functioning.

METHODS

The analyses included a subsample of nonanemic pregnant women recruited in early pregnancy and their children aged 4 years (n=295). Data were collected between 2013 and 2017 in Tarragona (Spain). On the basis of hemoglobin levels before the 12th gestational week, women receive different iron doses: 80 vs 40 mg/d if hemoglobin is 110-130 g/L and 20 vs 40 mg/d if hemoglobin >130 g/L. Children's cognitive functioning was assessed using the Wechsler Preschool and Primary Scale of Intelligence-IV and Developmental Neuropsychological Assessment-II tests. The analyses were carried out in 2022 after the completion of the study. Multivariate regression models were performed for assessing the association between different doses of prenatal iron supplementation and children's cognitive functioning.

RESULTS

Taking 80 mg/d of iron was positively associated with all the scales of the Wechsler Preschool and Primary Scale of Intelligence-IV and Neuropsychological Assessment-II when mothers had initial serum ferritin <15 µg/L, but it was negatively associated with Verbal Comprehension Index, Working Memory Index, Processing Speed Index, and Vocabulary Acquisition Index from Wechsler Preschool and Primary Scale of Intelligence-IV and verbal fluency index from Neuropsychological Assessment-II when mothers showed initial serum ferritin >65 µg/L. In the other group, taking 20 mg/d of iron was positively associated with Working Memory Index, Intelligence Quotient, verbal fluency, and emotion recognition indices when women had initial serum ferritin >65 µg/L.

CONCLUSIONS

Prenatal iron supplementation adjusted to the maternal hemoglobin levels and baseline iron stores improves cognitive functioning in children aged 4 years.

The Interaction between Psychological Stress and Iron Status on Early-Life Neurodevelopmental Outcomes

This review presents evidence from animal and human studies demonstrating the possible connection and significant impact of poor iron status and psychological distress on neurocognitive development during pregnancy and the neonatal period, with implications for long-term cognition. Stress and iron deficiency are independently prevalent and thus are frequently comorbid. While iron deficiency and early-life stress independently contribute to long-term neurodevelopmental alterations, their combined effects remain underexplored. Psychological stress responses may engage similar pathways as infectious stress, which alters fundamental iron metabolism processes and cause functional tissue-level iron deficiency. Psychological stress, analogous to but to a lesser degree than infectious stress, activates the hypothalamic-pituitary-adrenocortical (HPA) axis and increases proinflammatory cytokines. Chronic or severe stress is associated with dysregulated HPA axis functioning and a proinflammatory state. This dysregulation may disrupt iron absorption and utilization, likely mediated by the IL-6 activation of hepcidin, a molecule that impedes iron absorption and redistributes total body iron. This narrative review highlights suggestive studies investigating the relationship between psychological stress and iron status and outlines hypothesized mechanistic pathways connecting psychological stress exposure and iron metabolism. We examine findings regarding the overlapping impacts of early stress exposure to iron deficiency and children's neurocognitive development. We propose that studying the influence of psychological stress on iron metabolism is crucial for comprehending neurocognitive development in children exposed to prenatal and early postnatal stressors and for children at risk of early iron insufficiency. We recommend future directions for dual-exposure studies exploring iron as a potential mediating pathway between early stress and offspring neurodevelopment, offering opportunities for targeted interventions.

The Interactions between Maternal Iron Supplementation and Iron Metabolism-Related Genetic Polymorphisms on Birth Outcomes: A Prospective Study in Chinese

BACKGROUND

The effect of iron supplementation during pregnancy on birth outcomes may vary with maternal genetic background and needs more investigation.

OBJECTIVES

This prospective study aimed to evaluate the interactions between maternal iron supplementation and iron metabolism-related genetic polymorphisms on birth outcomes.

METHODS

This was a substudy from a community-based randomized control trial conducted in Northwest China, which included 860 women from the 2 micronutrient supplementation groups (folic acid [FA] and FA + iron group). Maternal peripheral blood, sociodemographic and health-related information, and neonatal birth outcomes were collected. Six single nucleotide polymorphisms in iron metabolism-related genes were genotyped. The alleles associated with decreased iron/hemoglobin status were used as the effect alleles. The genetic risk score (GRS) that reflected the genetic risk of low iron/hemoglobin status was estimated using the unweighted and weighted methods. Generalized estimating equations with small-sample corrections were applied to evaluate the interactions between iron supplementation and SNPs/GRS on birth outcomes.

RESULTS

There were significant interactions between maternal iron supplementation and rs7385804 (P = 0.009), rs149411 (P = 0.035), rs4820268 (P = 0.031), the unweighted GRS (P = 0.018), and the weighted GRS (P = 0.009) on birth weight. Compared with FA supplementation only, FA + iron supplementation significantly increased birth weight among women with more effect alleles in rs7385804 (β: 88.8 g, 95% CI: 9.2, 168.3) and the GRSs (the highest unweighted GRS, β: 135.5 g, 95% CI: 7.7, 263.4; the highest weighted GRS, β: 145.9 g, 95% CI: 43.4, 248.5); it had a trend of decreasing birth weight and increasing low birth weight risk among women with fewer effect alleles.

CONCLUSIONS

In our population, maternal genetic background related to iron metabolism plays a significant role in determining the efficacy of iron supplementation. Routine iron supplementation could be more beneficial to fetal weight growth among mothers with higher genetic risk for low iron/hemoglobin status.

Umbilical cord management - the first opportunity to improve healthcare disparities

This review focuses on iron deficiency and iron deficiency anemia in women and children in the United States. These are common, fixable problems that disproportionally affect minority populations. There are many opportunities for successful screening and management. The knowledge and awareness for identification and treatment of our populations' commonest deficiency is crucial.

Impact of iron supplementation on gestational diabetes mellitus: A literature review

Gestational diabetes mellitus (GDM) is a common complication of pregnancy, affecting 14% of pregnancies worldwide, and the prevention of pathological hyperglycaemia during pregnancy is meaningful for global public health. The role of iron supplementation in the progression of GDM has been of significant interest in recent years. Iron is a micronutrient that is vital during pregnancy; however, given the toxic properties of excess iron, it is probable that prophylactic iron supplementation will increase the risk of adverse pregnancy outcomes, including GDM. It is critical to clarify the effect of iron supplementation on the risk of GDM. Therefore, in this review, we comprehensively assess the role of iron in pregnancy. This review aimed to analyse the necessity of iron supplementation and maintenance of iron homeostasis during pregnancy, particularly reviewing the role and function of iron in beta cells and examining the mechanisms of excess iron contributing to the pathogenesis of GDM. Moreover, we aimed to discuss the association of haemoglobin and ferritin with GDM and identify priority areas for research.

Maternal iron status in early pregnancy and childhood body fat measures and cardiometabolic risk factors: A population-based prospective cohort

BACKGROUND

Whether maternal iron status during pregnancy is associated with cardiometabolic health in the offspring is poorly known.

OBJECTIVES

We aimed to assess the associations of maternal iron status during early pregnancy with body fat measures and cardiometabolic risk factors in children aged 10 y.

METHODS

In a population-based cohort study among 3718 mother-child pairs, we measured ferritin, transferrin, and transferrin saturation during early pregnancy. We obtained child BMI, fat mass index, and android/gynoid fat mass ratio by DXA, subcutaneous fat index, visceral fat index, pericardial fat index, and liver fat fraction by magnetic resonance imaging and assessed systolic and diastolic blood pressure, serum lipids, glucose, insulin, and CRP at 10 y.

RESULTS

A one-standard deviation score (SDS) higher maternal ferritin was associated with lower fat mass index [difference -0.05 (95% CI: -0.08, -0.02) SDS] and subcutaneous fat index [difference -0.06 (95% CI: -0.10, -0.02) SDS] in children. One-SDS higher maternal transferrin was associated with higher fat mass index [difference 0.04 (95% CI: 0.01, 0.07) SDS], android/gynoid fat mass ratio [difference 0.05 (95% CI: 0.02, 0.08) SDS], and subcutaneous fat index [difference 0.06 (95% CI: 0.02, 0.10) SDS] in children. Iron status during pregnancy was not consistently associated with organ fat and cardiometabolic risk factors at 10 y.

CONCLUSIONS

Maternal lower ferritin and higher transferrin in early pregnancy are associated with body fat accumulation and distribution but are not associated with cardiometabolic risk factors in childhood. Underlying mechanisms and long-term consequences warrant further study.

The Role of Iron and Cobalt in Gynecological Diseases

Iron and cobalt are micronutrients that play an important role in the regulation of cellular processes, being part of the centre of catalases, peroxidases, cytochromes and metalloproteins such as hemoglobin and myoglobin (Fe). Cobalt primarily functions as a component of hydroxycobalamin, which is essential for regulating red blood cell production. Maintaining normal levels of cobalt and iron in the human body is important, as a deficiency can lead to anaemia. These elements are also involved in reactions during which oxidative stress occurs and are therefore considered to be a cause of tumor formation. This paper will discuss aspects of the influence of cobalt and iron on mechanisms that may contribute to the growth of gynecological tumors, as well as other obstetric-gynecological disease entities, by altering the conditions of the microenvironment. In addition, the following review also highlights the role of cobalt and iron in the treatment of gynecological tumors.

The geo-spatial perspective of biological, social and environmental determinants of early pregnancy anaemia in rural Sri Lanka: Need for context-specific approaches on prevention

We provide a novel approach to understanding the multiple causations of maternal anaemia in a geospatial context, highlighting how genetics, environment and socioeconomic disparities at the micro-geographical level lead to the inequitable distribution of anaemia. All first-trimester pregnant women registered for the antenatal care programme in Anuradhapura District, Sri Lanka from July to September 2019 were invited to the Rajarata Pregnancy Cohort (RaPCo), which assessed the prevalence of anaemia in early pregnancy. The combination of the prevalence of anaemia and minor haemoglobinopathy-related anaemia (MHA) with the poverty headcount index of the 22 health divisions in the district was investigated using GeoDa spatial K-means clustering. Sociodemographic and economic data at the divisional level were compared between identified clusters. Combining the analysis with the geographical and environmental characteristics of the region, further hypotheses regarding anaemia in this community were formulated. The study included data from 3,137 pregnant women in early pregnancy. The anaemia and MHA prevalence varied from 13.6 to 21.7% and from 2.6% to 5%, respectively. We identified four distinct spatial clusters. The cluster with the highest anaemia prevalence also included high poverty and the highest prevalence of MHA. The clusters had significant differences with regard to ethnic distribution, access to water, sanitation and dietary patterns. Areas supplied by major irrigation projects had significantly low levels of anaemia, probably attributable to internal migration and improved livelihood. It was evident that genetic, socioeconomic and environmental risk factors were grouped at the divisional level, and that their complex interactions make controlling anaemia with blanket interventions unsuccessful. Analysis of the distribution of heterogeneous risk factors at the micro-geospatial level helped identify context-specific approaches to tackle anaemia in pregnancy.

Iron Supplementation in Pregnancy and Risk of Gestational Diabetes: A Narrative Review

Pregnant women frequently supplement their diets with iron to treat any cryptic anemia, on the assumption that if anemia is not present, there will be no negative consequences. However, in women who are already iron-replete, it has been suggested that this can lead to iron overload and an increased risk of certain pregnancy complications. One such complication is gestational diabetes. Fourteen clinical trials, case-control or cohort studies (found using Pubmed/Scopus/Web of Science) have investigated links between iron supplementation in pregnancy and risk of gestational diabetes, several of them finding significant associations with increased risk. Potential mechanisms include increased oxidative stress leading to insulin resistance and inadequate compensatory insulin secretion. Current evidence suggests that dietary supplementation with iron in pregnancy may increase a pregnant woman's chance of developing gestational diabetes, although available evidence is somewhat contradictory, and the magnitude of any increased risk appears relatively small. Meta-analyses have suggested the presence of significant heterogeneity in results between studies, urging a degree of caution in interpreting these results. It is currently suggested that advice to pregnant women about whether to supplement their diets with iron or not should consider both their current iron status and their other established risk factors for gestational diabetes.

Factors associated with early pregnancy anemia in rural Sri Lanka: Does being 'under care' iron out socioeconomic disparities?

Globally, more than a third of pregnant women are anemic, and progress in its prevention and control is slow. Sri Lanka is a lower-middle-income country with a unique public health infrastructure that provides multiple interventions across the lifecycle for anemia prevention, despite which anemia in pregnancy remains a challenge. Studying the factors associated with maternal anemia in this context would provide unique information on challenges and opportunities encountered as low-and-middle-income countries attempt to control anemia by improving health care coverage. All first-trimester pregnant women registered for antenatal care in the Anuradhapura district between July 2019 to September 2019 were invited to participate in the baseline of a cohort study. Interviewer-administered and self-completed questionnaires were used. Anemia was defined using a full blood count. A hierarchical logistic regression model was built to identify factors associated with anemia. Out of 3127 participants, 451 (14.4%) were anemic. According to the regression model (Chi-square = 139.3, p<0.001, n = 2692), the odds of being anemic increased with the Period of gestation (PoG) (OR = 1.07, 95% CI = 1.01-1.13). While controlling for PoG, age and parity, history of anemia (OR = 3.22, 95%CI = 2.51-4.13), being underweight (OR = 1.64, 95%CI = 1.24-2.18), having the last pregnancy five or more years back (OR = 1.57,95%CI = 1.15-2.15) and having used intrauterine devices for one year or more (OR = 1.63, 95%CI = 1.16-2.30) increased the odds of anemia. Breast feeding during the last year (OR = 0.66, 95%CI = 0.49-0.90) and having used contraceptive injections for one year or more (OR = 0.61,95%CI = 0.45-0.83) reduced the risk of anemia. Proxy indicators of being in frequent contact with the national family health program have a protective effect over the socioeconomic disparities in preventing early pregnancy anemia. Maintaining the continuum of care through the lifecycle, especially through optimizing pre and inter-pregnancy care provision should be the way forward for anemia control.

Evaluation of Heavy Metals in Soil Wastewater Stream

Environmental pollution is one of the main factors that significantly affect biological systems and human health. Soil pollution with heavy metals is an increasingly pressing problem worldwide. In general, heavy metals are stable and do not decompose, unlike other organic pollutants. The quantity of them is natural components of soil crust, the remaining come from human activities, which may result from the extensive use of sewage. In the present study, a methodology aimed at simultaneous quantification of 16 heavy elements in soil of 3 different regions was developed. The concentration of 16 soil heavy metals (Se, Cd, V, Be, As, Mn, Co, Zn, Fe, Cr, Pb, Ni, Cu, Mo, Hg, and Ti) was measured in 11 sampling along Riyadh, Qassim, and Medina, Kingdom of Saudi Arabia from 3 sites soil treated with sewage water. These chemical minerals were identified in the samples using an ICPE-9000 spectrometer. The assessment of heavy metal contamination was derived using enrichment factors (EF), the pollution load index (PLI), and geoaccumulation index (I_geo). This study revealed that the soil is predominantly polluted by Cd, As, and Mo of Riyadh and Medina and As, Mo, and Cd of Qassim region at site B and site C, respectively. As recorded, the highest concentration value of 5000 mg/kg for Fe at site (B) followed by Cu. The I_geo value of Cd is 1.1520 in Medina region. The I_geo value of Se is 3.2395 in Medina region, while its cumulative geographical index decreased in the regions of Riyadh and Qassim, which amounted to 2.6114 and 2.1699, respectively. The I_geo values of the rest of the minerals in the three regions studied indicated that the soil is unpolluted, while it was slightly to moderately polluted for both Mo and Hg in most regions studied. The minerals in the soil at all sites studied were less than the general average concentration. With the exception of mercury, molybdenum, arsenic, cadmium, and selenium, whose concentration exceeded the permissible and recommended limits. The increasing order of concentration of minerals was Be < V < Cd < Hg < Mo < Co < Zn < Pb < Cr < Se < As < Ni < Ti < Mn < Cu < Fe at all sites, respectively.

Multiple Indicators of Undernutrition, Infection, and Inflammation in Lactating Women Are Associated with Maternal Iron Status and Infant Anthropometry in Panama: The MINDI Cohort

Maternal infections, nutrient deficiencies, and inflammation (MINDI) co-exist in lactating indigenous women in Panama, but their impact on maternal iron status and infant growth is unknown. For this secondary analysis of cross-sectional data of lactating mothers from our MINDI cohort, we investigated associations of MINDI variables with maternal anemia, elevated serum transferrin receptor (sTfR), low serum iron, hepcidin, ferritin, and infant weight-for-age (WAZ), length-for-age (LAZ), and head-circumference-for-age (HCAZ) Z-scores in 99 mother-infant dyads. A bootstrapping resampling procedure preselected covariates for inclusion in multivariable regressions models from chronic maternal infections and nutritional status [folate, vitamins A, D, retinol-binding protein (RBP), insulin-growth factor-1 (IGF-1)] and inflammation [C-reactive protein (CRP), cytokines, platelet indices] indicators. Anemia was prevalent (53.5%) but underestimated due to widespread low plasma volume (<2.2 L, 79.9%) and was associated with indicators of malnutrition [lower IGF-1, body mass index (BMI), vitamin D, and intake of green/leafy vegetables], but not inflammation. Higher CRP was associated with lower serum iron, and higher hepcidin and ferritin, whereas maternal platelets were associated with lower HCAZ (β = −0.22), WAZ (β = −0.17), and LAZ (β = −0.17). Higher LAZ was also associated with maternal serum vitamin D (β = 0.23), whereas maternal iron supplementation lowered LAZ (β = −0.22). Assessment of iron status in this MINDI cohort is complex and supplementation strategies must consider consequences for both the mother and the infant.

Maternal Iron Deficiency Programs Rat Offspring Hypertension in Relation to Renin—Angiotensin System and Oxidative Stress

Hypertension is an important public health challenge, affecting up to 30–50% of adults worldwide. Several epidemiological studies indicate that high blood pressure originates in fetal life—the so-called programming effect or developmental origin of hypertension. Iron-deficiency anemia has become one of the most prevalent nutritional problems globally. Previous animal experiments have shown that prenatal iron-deficiency anemia adversely affects offspring hypertension. However, the underlying mechanism remains unclear. We used a maternal low-iron diet Sprague Dawley rat model to study changes in blood pressure, the renal renin-angiotensin system, oxidative stress, inflammation, and sodium transporters in adult male offspring. Our study revealed that 16-week-old male offspring born to mothers with low dietary iron throughout pregnancy and the lactation period had (1) higher blood pressure, (2) increased renal cortex angiotensin II receptor type 1 and angiotensin-converting enzyme abundance, (3) decreased renal cortex angiotensin II receptor type 2 and MAS abundance, and (4) increased renal 8-hydroxy-2′-deoxyguanosine and interleukin-6 abundance. Improving the iron status of pregnant mothers could influence the development of hypertension in their offspring.

Maternal heme-enriched diet promotes a gut pro-oxidative status associated with microbiota alteration, gut leakiness and glucose intolerance in mice offspring

Maternal environment, including nutrition and microbiota, plays a critical role in determining offspring's risk of chronic diseases such as diabetes later in life. Heme iron requirement is amplified during pregnancy and lactation, while excessive dietary heme iron intake, compared to non-heme iron, has shown to trigger acute oxidative stress in the gut resulting from reactive aldehyde formation in conjunction with microbiota reshape. Given the immaturity of the antioxidant defense system in early life, we investigated the extent to which a maternal diet enriched with heme iron may have a lasting impact on gut homeostasis and glucose metabolism in 60-day-old C3H/HeN mice offspring.

As hypothesized, the form of iron added to the maternal diet differentially governed the offspring's microbiota establishment despite identical fecal iron status in the offspring. Importantly, despite female offspring was unaffected, oxidative stress markers were however higher in the gut of male offspring from heme enriched-fed mothers, and were accompanied by increases in fecal lipocalin-2, intestinal para-cellular permeability and TNF-α expression. In addition, male mice displayed blood glucose intolerance resulting from impaired insulin secretion following oral glucose challenge. Using an integrated approach including an aldehydomic analysis, this male-specific phenotype was further characterized and revealed close covariations between unidentified putative reactive aldehydes and bacterial communities belonging to Bacteroidales and Lachnospirales orders.

Our work highlights how the form of dietary iron in the maternal diet can dictate the oxidative status in gut offspring in a sex-dependent manner, and how a gut microbiota-driven oxidative challenge in early life can be associated with gut barrier defects and glucose metabolism disorders that may be predictive of diabetes development.

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Maternal heminic vs. non-heminic iron intake differentially and persistently imprints the offspring's fecal microbiota.

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Males from heme-fed dams exhibit increased gut lumen reactive aldehydes in absence of direct dietary exposure to heme iron.

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Some of the increased reactive aldehydes closely covariated with Orders belonging to Bacteroidales and Lachnospirales.

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Maternal exposure to dietary heme iron impairs gut barrier and glucose tolerance in male offspring.

Ethnic differences in adverse iron status in early pregnancy: a cross-sectional population-based study

We studied ethnic differences in terms of iron status during pregnancy between Dutch women and other ethnicities and explore to what extent these differences can be explained by environmental factors. This cross-sectional population-based study (2002-2006) was embedded in the Generation R study and included a total of 4737 pregnant women from seven ethnic groups (Dutch, Turkish, Moroccan, Cape Verdean, Surinamese-Hindustani, Surinamese-Creole and Antillean). Ethnicity was defined according to the Dutch classification of ethnic background. Ferritin, iron and transferrin were measured in early pregnancy. The overall prevalence of iron deficiency was 7 %, ranging from 4 % in both Dutch and Surinamese-Creoles, to 18 % in Turkish, Moroccan and Surinamese-Hindustani women. Iron overload was most prevalent in Surinamese-Creole (11 %) and Dutch (9 %) women. Socioeconomic factors accounted for 5-36 % of the differences. Income was the strongest socioeconomic factor in the Cape Verdean and Surinamese-Hindustani groups and parity for the Turkish and Moroccan groups. Lifestyle determinants accounted for 8-14 % of the differences. In all groups, the strongest lifestyle factor was folic acid use, being associated with higher iron status. In conclusion, in our population, both iron deficiency and iron overload were common in early pregnancy. Our data suggest that ethnic differences in terms of socioeconomic and lifestyle factors only partly drive the large ethnic differences in iron status. Our data support the development of more specific prevention programmes based on further exploration of socioeconomic inequities, modifiable risk and genetic factors in specific ethnic subgroups, as well as the need for individual screening of iron status before supplementation.

Associations between maternal iron supplementation in pregnancy and offspring growth and cardiometabolic risk outcomes in infancy and childhood

It was previously observed that maternal iron supplementation in pregnancy was associated with increased offspring size and adiposity at birth, possibly mediated through increased risk of gestational diabetes. In this study we investigated potential long-term associations of maternal iron supplementation in pregnancy with offspring growth in infancy, and growth and cardiometabolic risk factors in mid-childhood to seek evidence of nutritional programming. Using a nested case-control format, markers of growth and adiposity were measured at 3, 12 and 24 months of age in 341 infants from the Cambridge Baby Growth Study whose mothers supplemented with iron in pregnancy and 222 infants whose mothers did not. Measures of growth, glucose tolerance (using a 30 minute 1.75 g glucose/kg body weight oral glucose tolerance test), insulin sensitivity (HOMA IR) and blood pressure were collected in 122 and 79 of these children, respectively, at around 9.5 years of age. In infancy adiposity-promoting associations with maternal iron supplementation in pregnancy were evident at 3 months of age (e.g. mean difference in skinfold thickness: β = +0.15 mm, p = 0.02, in n = 341 whose mothers supplemented versus 222 that did not; waist circumference: β = +0.7 cm, p = 0.04, in n = 159 and 78, respectively) but differences lessened after this time (e.g. 3–12 month change in mean difference in skinfold thickness: β = -0.2 mm, p = 0.03, in n = 272 and 178, respectively). At ~9.5 years of age children whose mothers supplemented with iron in pregnancy had lower mean arterial blood pressures (β = -1.0 mmHg, p = 0.03, in n = 119 and 78, respectively). There were no apparent differences in markers of growth or other cardiometabolic factors. These results suggest that most of the associations of maternal iron supplementation in pregnancy on growth and adiposity evident at birth disappear during infancy, but there may be some evidence of long-term nutritional programming of blood pressure in mid-childhood.

Maternal iron status in early pregnancy and DNA methylation in offspring: an epigenome-wide meta-analysis

BACKGROUND

Unbalanced iron homeostasis in pregnancy is associated with an increased risk of adverse birth and childhood health outcomes. DNA methylation has been suggested as a potential underlying mechanism linking environmental exposures such as micronutrient status during pregnancy with offspring health. We performed a meta-analysis on the association of maternal early-pregnancy serum ferritin concentrations, as a marker of body iron stores, and cord blood DNA methylation. We included 1286 mother-newborn pairs from two population-based prospective cohorts. Serum ferritin concentrations were measured in early pregnancy. DNA methylation was measured with the Infinium HumanMethylation450 BeadChip (Illumina). We examined epigenome-wide associations of maternal early-pregnancy serum ferritin and cord blood DNA methylation using robust linear regression analyses, with adjustment for confounders and performed fixed-effects meta-analyses. We additionally examined whether associations of any CpGs identified in cord blood persisted in the peripheral blood of older children and explored associations with other markers of maternal iron status. We also examined whether similar findings were present in the association of cord blood serum ferritin concentrations with cord blood DNA methylation.

RESULTS

Maternal early-pregnancy serum ferritin concentrations were inversely associated with DNA methylation at two CpGs (cg02806645 and cg06322988) in PRR23A and one CpG (cg04468817) in PRSS22. Associations at two of these CpG sites persisted at each of the follow-up time points in childhood. Cord blood serum ferritin concentrations were not associated with cord blood DNA methylation levels at the three identified CpGs.

CONCLUSION

Maternal early-pregnancy serum ferritin concentrations were associated with lower cord blood DNA methylation levels at three CpGs and these associations partly persisted in older children. Further studies are needed to uncover the role of these CpGs in the underlying mechanisms of the associations of maternal iron status and offspring health outcomes.

Scientific advice related to nutrient profiling for the development of harmonised mandatory front-of-pack nutrition labelling and the setting of nutrient profiles for restricting nutrition and health claims on foods

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver scientific advice related to nutrient profiling for the development of harmonised mandatory front‐of‐pack nutrition labelling and the setting of nutrient profiles for restricting nutrition and health claims on foods. This Opinion is based on systematic reviews and meta‐analyses of human studies on nutritionally adequate diets, data from the Global Burden of Disease framework, clinical practice guidelines, previous EFSA opinions and the priorities set by EU Member States in the context of their Food‐Based Dietary Guidelines and associated nutrient/food intake recommendations. Relevant publications were retrieved through comprehensive searches in PubMed. The nutrients included in the assessment are those likely to be consumed in excess or in inadequate amounts in a majority of European countries. Food groups with important roles in European diets have been considered. The Panel concludes that dietary intakes of saturated fatty acids (SFA), sodium and added/free sugars are above, and intakes of dietary fibre and potassium below, current dietary recommendations in a majority of European populations. As excess intakes of SFAs, sodium and added/free sugars and inadequate intakes of dietary fibre and potassium are associated with adverse health effects, they could be included in nutrient profiling models. Energy could be included because a reduction in energy intake is of public health importance for European populations. In food group/category‐based nutrient profiling models, total fat could replace energy in most food groups owing to its high‐energy density, while the energy density of food groups with low or no fat content may be well accounted for by the inclusion of (added/free) sugars. Some nutrients may be included in nutrient profiling models for reasons other than their public health importance, e.g. as a proxy for other nutrients of public health importance, or to allow for a better discrimination of foods within the same food category.

Cross-sectional study to assess etiology and associated factors for anaemia during first trimester of pregnancy in Anuradhapura District, Sri Lanka: a protocol

Background: Anaemia in pregnancy, which can lead to adverse maternal and fetal outcomes, is a significant global health problem. Despite Sri Lanka’s strong public health system and commitment towards prevention, maternal anaemia remains a major problem in the country. While prevention is focused on iron deficiency, detailed etiological studies on this topic are scarce. Moreover, estimates of socio demographic and economic factors associated with anaemia in pregnancy, which can provide important clues for anaemia control, are also lacking. This study aims to evaluate the hemoglobin distribution, and geographical distribution, contribution of known aetiologies and associated factors for anaemia in pregnant women in Anuradhapura, Sri Lanka.

Methods: This is a cross sectional study of pregnant women in their first trimester registered for antenatal care from July to September 2019 in Anuradhapura district. The minimal sample size was calculated to be 1866. Initial data collection has already been carried out in special field clinics for pregnant women between June to October 2019. An interviewer-administered questionnaire, a self-completed dietary questionnaire and an examination checklist were used for data collection. In addition, all participants underwent complete blood count testing. Further investigations are being conducted for predicting the etiology of anaemia based on a developed algorithm (such as high-performance liquid chromatography [HPLC] and peripheral blood film analysis).

Discussion: Being the largest study on anaemia during pregnancy in a single geographical area in Sri Lanka, this study will provide important clues about geographical clustering of anaemia cases with similar etiology, associated factors and etiologies which would help to develop interventions to improve the health of pregnant women in the area. The possibility of selection bias is a potential limitation associated with the study design.

Prevalence and aetiologies of anaemia among first trimester pregnant women in Sri Lanka; the need for revisiting the current control strategies

BACKGROUND

The Sustainable development goals, which focus strongly on equity, aim to end all forms of malnutrition by 2030. However, a significant cause of intergenerational transfer of malnutrition, anaemia in pregnancy, is still a challenge. It is especially so in the low- and middle-income settings where possible context-specific aetiologies leading to anaemia have been poorly explored. This study explores the prevalence of etiological factors significantly contributing to anaemia in pregnancy in Sri Lanka, a lower-middle-income country with a high prevalence of malnutrition albeit robust public health infrastructure.

METHODS

All first-trimester pregnant women registered in the public maternal care programme in the Anuradhapura district from July to September 2019 were invited to participate in Rajarata Pregnancy Cohort (RaPCo). After a full blood count analysis, high-performance liquid chromatography, peripheral blood film examination, serum B12 and folate levels were performed in anaemic participants, guided by an algorithm based on the red cell indices in the full blood count. In addition, serum ferritin was tested in a random subsample of 213 participants. Anaemic women in this subsample underwent B12 and folate testing.

RESULTS

Among 3127 participants, 14.4% (95%CI 13.2-15.7, n = 451) were anaemic. Haemoglobin ranged between 7.4 to 19.6 g/dl. 331(10.6%) had mild anaemia. Haemoglobin ≥13 g/dl was observed in 39(12.7%). Microcytic, normochromic-normocytic, hypochromic-normocytic and macrocytic anaemia was observed in 243(54%), 114(25.3%), 80(17.8%) and two (0.4%) of full blood counts in anaemic women, respectively. Microcytic anaemia with a red cell count ≥5 * 106 /μl demonstrated a 100% positive predictive value for minor haemoglobinopathies. Minor hemoglobinopathies were present in at least 23.3%(n = 105) of anaemic pregnant women. Prevalence of iron deficiency, B12 deficiency and Southeast Asian ovalocytosis among the anaemic was 41.9% (95%CI 26.4-59.2), 23.8% (95%CI 10.6-45.1) and 0.9% (95%CI 0.3-2.3%), respectively. Folate deficiency was not observed.

CONCLUSION

Even though iron deficiency remains the primary cause, minor hemoglobinopathies, B 12 deficiency and other aetiologies substantially contribute to anaemia in pregnancy in this study population. Public health interventions, including screening for minor hemoglobinopathies and multiple micronutrient supplementation in pregnancy, should be considered in the national programme for areas where these problems have been identified.

Neurological development and iron supplementation in healthy late-preterm neonates: a randomized double-blind controlled trial

Late-preterm infants (LPT) are at increased risk for long-term neurodevelopmental sequelae and iron deficiency. The aim of the study is to assess the positive effect of iron supplementation on psychomotor development in healthy LPT. We designed a randomized placebo-controlled double-blind trial dividing the newborns into two groups. Every patient was assessed using the Griffiths Mental Development Scales (GMDS)-II edition at 12-month post-conceptional age. The study was performed at the Neonatology Unit of our Hospital, in Italy. Sixty-six healthy LPT infants born between 340⁄7 and 366⁄7 weeks of gestational age were enrolled in the study. One group received martial prophylaxis from the third week of life to 6 months of post-conceptional age (2 mg/kg/day of iron pidolate), the other received placebo. Fifty-two of the enrolled infants were assessed using the GMDS at 12-month of post-conceptional age. Statistical analysis of the mean scores of the Griffiths subscales was performed. There was a difference in the mean developmental quotient (DQ) (p < 0.01) between the two groups: iron group mean DQ 121.45 ± 10.53 vs placebo group mean DQ 113.25 ± 9.70. Moreover, mean scores of the Griffiths subscales A, B, and D showed significant differences between the two groups (scale A p < 0.05, scale B p < 0.02, scale D p < 0.01, respectively).Conclusions: We recommend that all LPT neonates receive iron supplementation during the first 6 months of life in order to improve their 1-year neurodevelopmental quotient. What is Known: • Late-preterm infants (LPT) are at increased risk for long-term neurodevelopmental sequelae and also for iron deficiency. • Iron deficiency is an independent risk factor for adverse neurological outcomes. What is New: • Healthy late-preterm who received iron supplementation during the first 6 months of life achieved better neurological outcomes at 12-month post-conceptional age than LPT who received placebo. • Our study strongly supports the need for the implementation of martial prophylaxis in LPT neonates.

Chronic Heart Failure: Clinical Implications of Iron Homeostasis Disturbances Revisited

Iron deficiency is prevalent in chronic heart failure (CHF) patients. Nonetheless, the diagnosis is often overlooked and, often, the treatment is commenced just when overt anemia has ensued. Therefore, a better appreciation of this disease is needed, and all seasoned cardiologists should know how to approach CHF patients with iron deficiency correctly, as mandated by clinical practice guidelines. In this comprehensive review, we describe iron homeostasis, the pathophysiologic changes of iron homeostasis, and the clinical implications of iron deficiency on CHF patients. In addition, we delineate the evolution of clinical trials, ranging from the inception to the ongoing clinical trials of iron deficiency treatment in CHF patients. Iron deficiency contributes to the worse clinical outcome of the patients. Numerous studies have reported the clinical benefit of iron supplementation, particularly in intravenous preparation, in heart failure patients regarding symptoms, functional capacity, and quality of life (QoL) improvement. Therefore, the current guidelines recommend routine screening of iron status in all newly diagnosed heart failure patients. Eventually, intravenous iron replacement is recommended for symptomatic heart failure patients with iron deficiency, irrespective of anemia.

Disparities in Risks of Inadequate and Excessive Intake of Micronutrients during Pregnancy

BACKGROUND

Inadequate or excessive intake of micronutrients in pregnancy has potential to negatively impact maternal/offspring health outcomes.

OBJECTIVE

The aim was to compare risks of inadequate or excessive micronutrient intake in diverse females with singleton pregnancies by strata of maternal age, race/ethnicity, education, and prepregnancy BMI.

METHODS

Fifteen observational cohorts in the US Environmental influences on Child Health Outcomes (ECHO) Consortium assessed participant dietary intake with 24-h dietary recalls (n = 1910) or food-frequency questionnaires (n = 7891) from 1999-2019. We compared the distributions of usual intake of 19 micronutrients from food alone (15 cohorts; n = 9801) and food plus dietary supplements (10 cohorts with supplement data; n = 7082) to estimate the proportion with usual daily intakes below their age-specific daily Estimated Average Requirement (EAR), above their Adequate Intake (AI), and above their Tolerable Upper Intake Level (UL), overall and within sociodemographic and anthropometric subgroups.

RESULTS

Risk of inadequate intake from food alone ranged from 0% to 87%, depending on the micronutrient and assessment methodology. When dietary supplements were included, some women were below the EAR for vitamin D (20-38%), vitamin E (17-22%), and magnesium (39-41%); some women were above the AI for vitamin K (63-75%), choline (7%), and potassium (37-53%); and some were above the UL for folic acid (32-51%), iron (39-40%), and zinc (19-20%). Highest risks for inadequate intakes were observed among participants with age 14-18 y (6 nutrients), non-White race or Hispanic ethnicity (10 nutrients), less than a high school education (9 nutrients), or obesity (9 nutrients).

CONCLUSIONS

Improved diet quality is needed for most pregnant females. Even with dietary supplement use, >20% of participants were at risk of inadequate intake of ≥1 micronutrients, especially in some population subgroups. Pregnancy may be a window of opportunity to address disparities in micronutrient intake that could contribute to intergenerational health inequalities.

Iron and Neurodevelopment in Preterm Infants: A Narrative Review

Iron is critical for brain development, playing key roles in synaptogenesis, myelination, energy metabolism and neurotransmitter production. NICU infants are at particular risk for iron deficiency due to high iron needs, preterm birth, disruptions in maternal or placental health and phlebotomy. If deficiency occurs during critical periods of brain development, this may lead to permanent alterations in brain structure and function which is not reversible despite later supplementation. Children with perinatal iron deficiency have been shown to have delayed nerve conduction speeds, disrupted sleep patterns, impaired recognition memory, motor deficits and lower global developmental scores which may be present as early as in the neonatal period and persist into adulthood. Based on this, ensuring brain iron sufficiency during the neonatal period is critical to optimizing neurodevelopmental outcomes and iron supplementation should be targeted to iron measures that correlate with improved outcomes.

Iron status in late pregnancy is inversely associated with birth weight in Colombia

OBJECTIVE

Gestational anaemia (GA) is common in developing countries. This study assessed the relationship of late GA and negative perinatal outcomes in participants recruited in a reference maternity unit of the Caribbean region of Colombia.

DESIGN

Prospective analytical birth cohort study. Maternal Hb and serum ferritin (SF) levels were measured. GA was defined as Hb levels <6·82 mmol/l (<11 g/dl), SF depletion as SF levels <12 µg/l. Birth outcomes such as low birth weight (LBW), preterm birth (PB) and small for gestational age (SGA) were examined.

SETTING

Mothers in the first stage of labour, living in urban or rural areas of Bolívar, were enrolled in an obstetrical centre located in Cartagena, Colombia. Blood and stool samples were taken prior delivery. Maternal blood count, SF levels and infant anthropometric data were recorded for analysis.

PARTICIPANTS

1218 pregnant women aged 18-42 years and their newborns.

RESULTS

Prevalence of GA and SF depletion was 41·6 % and 41·1 %, respectively. GA was positively associated with poverty-related sociodemographic conditions. Prenatal care attendance lowered the risk of PB, LBW and SGA. Birth weight was inversely associated with Hb levels, observing a -36·8 g decrease in newborn weight per 0·62 mmol/l (or 1 g/dl) of maternal Hb. SF depletion, but not anaemia, was associated with PB. SGA outcome showed a significant association with anaemia, but not a significant relationship with SF depletion.

CONCLUSIONS

Birth weight and other-related perinatal outcomes are negatively associated with Hb and SF depletion. Prenatal care attendance reduced the risk of negative birth outcomes.

Crosstalk of fibroblast growth factor 23 and anemia-related factors during the development and progression of CKD (Review)

Fibroblast growth factor 23 (FGF23) plays an important role in the development of chronic kidney disease-mineral bone disorder (CKD-MBD). Abnormally elevated levels of 1,25-dihydroxyvitamin D cause osteocytes to secrete FGF23, which subsequently induces phosphaturia. Recent studies have reported that iron deficiency, erythropoietin (EPO) and hypoxia regulate the pathways responsible for FGF23 production. However, the molecular mechanisms underlying the interactions between FGF23 and anemia-related factors are not yet fully understood. The present review discusses the associations between FGF23, iron, EPO and hypoxia-inducible factors (HIFs), and their impact on FGF23 bioactivity, focusing on recent studies. Collectively, these findings propose interactions between FGF23 gene expression and anemia-related factors, including iron deficiency, EPO and HIFs. Taken together, these results suggest that FGF23 bioactivity is closely associated with the occurrence of CKD-related anemia and CKD-MBD.

Nutrition in Pregnancy: A Comparative Review of Major Guidelines

Importance

Nutrition patterns in pregnancy play a decisive role in the well-being of the mother and the fetus.

Objective

The aim of this review was to summarize and compare guidelines and recommendations on nutrition in pregnancy.

Evidence Acquisition

A descriptive review of major guidelines on antenatal nutrition was conducted, including the most recently published guidelines, namely, by the Australian Government Department of Health (2018); the Canadian Nutrition Working Group and Society of Obstetricians and Gynaecologists of Canada (2016); the World Health Organization (2016); the Institute of Obstetricians and Gynaecologists, Royal College of Physicians of Ireland (2016); the International Federation of Gynecology and Obstetrics (2015); the Academy of Nutrition and Dietetics (2014); and the National Institute for Health and Care Excellence (2008).

Results

There is almost universal agreement regarding macronutrient requirements during pregnancy. The WHO, FIGO, and the NICE guidelines make no recommendation on fluid intake. Almost all guidelines state that weight gain during pregnancy should be closely monitored. Folic acid supplementation is universally recommended from the preconception period, but there are controversies regarding other vitamins' supplementation. Multiple micronutrient supplementation could be an option in specific settings according only to the FIGO. Probiotics are not routinely recommended in pregnancy.

Conclusions

There is wide agreement among the reviewed guidelines regarding nutrition in pregnancy, but still there are controversies. Evaluation and classification of influential guidelines can be beneficial for establishing a universal consensus on nutrition during pregnancy, in order to achieve more favorable perinatal outcomes.

Maternal Iron Status in Pregnancy and Child Health Outcomes after Birth: A Systematic Review and Meta-Analysis

In pregnancy, iron deficiency and iron overload increase the risk for adverse pregnancy outcomes, but the effects of maternal iron status on long-term child health are poorly understood. The aim of the study was to systematically review and analyze the literature on maternal iron status in pregnancy and long-term outcomes in the offspring after birth. We report a systematic review on maternal iron status during pregnancy in relation to child health outcomes after birth, from database inception until 21 January 2021, with methodological quality rating (Newcastle-Ottawa tool) and random-effect meta-analysis. (PROSPERO, CRD42020162202). The search identified 8139 studies, of which 44 were included, describing 12,7849 mother–child pairs. Heterogeneity amongst the studies was strong. Methodological quality was predominantly moderate to high. Iron status was measured usually late in pregnancy. The majority of studies compared categories based on maternal ferritin, however, definitions of iron deficiency differed across studies. The follow-up period was predominantly limited to infancy. Fifteen studies reported outcomes on child iron status or hemoglobin, 20 on neurodevelopmental outcomes, and the remainder on a variety of other outcomes. In half of the studies, low maternal iron status or iron deficiency was associated with adverse outcomes in children. Meta-analyses showed an association of maternal ferritin with child soluble transferrin receptor concentrations, though child ferritin, transferrin saturation, or hemoglobin values showed no consistent association. Studies on maternal iron status above normal, or iron excess, suggest deleterious effects on infant growth, cognition, and childhood Type 1 diabetes. Maternal iron status in pregnancy was not consistently associated with child iron status after birth. The very heterogeneous set of studies suggests detrimental effects of iron deficiency, and possibly also of overload, on other outcomes including child neurodevelopment. Studies are needed to determine clinically meaningful definitions of iron deficiency and overload in pregnancy.

Marginally reduced maternal hepatic and splenic ferroportin under severe nutritional iron deficiency in pregnancy maintains systemic iron supply

The demand for iron is high in pregnancy to meet the increased requirements for erythropoiesis. Even pregnant females with initially iron‐replete stores develop iron‐deficiency anemia, due to inadequate iron absorption. In anemic females, the maternal iron supply is dedicated to maintaining iron metabolism in the fetus and placenta. Here, using a mouse model of iron deficiency in pregnancy, we show that iron recycled from senescent erythrocytes becomes a predominant source of this microelement that can be transferred to the placenta in females with depleted iron stores. Ferroportin is a key protein in the molecular machinery of cellular iron egress. We demonstrate that under iron deficiency in pregnancy, levels of ferroportin are greatly reduced in the duodenum, placenta and fetal liver, but not in maternal liver macrophages and in the spleen. Although low expression of both maternal and fetal hepcidin predicted ferroportin up‐regulation in examined locations, its final expression level was very likely correlated with tissue iron status. Our results argue that iron released into the circulation of anemic females is taken up by the placenta, as evidenced by high expression of iron importers on syncytiotrophoblasts. Then, a substantial decrease in levels of ferroportin on the basolateral side of syncytiotrophoblasts, may be responsible for the reduced transfer of iron to the fetus. As attested by the lowest decrease in iron content among analyzed tissues, some part is retained in the placenta. These findings confirm the key role played by ferroportin in tuning iron turnover in iron‐deficient pregnant mouse females and their fetuses.

The effect of Lactiplantibacillus plantarum 299v together with a low dose of iron on iron status in healthy pregnant women: A randomized clinical trial

Introduction

Iron deficiency during pregnancy is a global health problem and is associated with adverse pregnancy outcomes. The aim of this randomized, double‐blind, placebo‐controlled study was to evaluate the effect of Lactiplantibacillus plantarum 299v (Lp299v, 10¹⁰ colony forming units), 4.2 mg iron, 12 mg ascorbic acid and 30 µg folic acid (Lp) on iron status in healthy, non‐anemic, pregnant Swedish women.

Material and methods

A total of 326 women were randomized to receive Lp (n = 161) or placebo (n = 165) twice daily from gestational week 10–12 until end of pregnancy or until the potential start of iron therapy. The primary endpoint was serum ferritin at week 28.

Results

Intake of Lp attenuated the decrease in serum ferritin from baseline to week 28 (p = 0.003) and week 35 (p ˂ 0.001) and resulted in reduced prevalence of iron deficiency (59% vs 78%, p = 0.017) and iron deficiency anemia (7.4% vs 21%, p = 0.023) at week 35. Intake of Lp also resulted in beneficial effects on the soluble transferrin receptor (p = 0.011) and total body iron (p ˂ 0.001) at week 35. Gestational length and birthweight were comparable between groups. The proportion of women reporting adverse events during the study was comparable between groups.

Conclusions

Intake of Lp from early pregnancy was safe, attenuated the loss of iron stores and improved iron status in healthy pregnant women.

Iron stores at birth in a full-term normal birth weight birth cohort with a low level of inflammation

Iron stores at birth are essential to meet iron needs during the first 4-6 months of life. The present study aimed to investigate iron stores in normal birth weight, healthy, term neonates. Umbilical cord blood samples were collected from apparently normal singleton vaginal deliveries (n=854). Subjects were screened and excluded if C-reactive protein (CRP) > 5 mg/l or α1-acid glycoprotein (AGP) > 1 g/l, preterm (<37 complete weeks), term < 2500g or term > 4000g. In total, 762 samples were included in the study. Serum ferritin, soluble transferrin receptor (sTfR), hepcidin, and erythropoietin (EPO) were measured in umbilical cord blood samples; total body iron (TBI) (mg/kg) was calculated using sTfR and ferritin concentrations. A total of 19.8% newborns were iron deficient (ferritin 35 μg/l) and an additional 46.6% had insufficient iron stores (ferritin < 76 μg/l). There was a positive association between serum ferritin and sTfR, hepcidin, and EPO. Gestational age was positively associated with ferritin, sTfR, EPO, and hepcidin. In conclusion, we demonstrate a high prevalence of insufficient iron stores in a Chinese birth cohort. The value of cord sTfR and TBI in the assessment of iron status in the newborn is questionable, and reference ranges need to be established.

Dietary Iron Intake in Excess of Requirements Impairs Intestinal Copper Absorption in Sprague Dawley Rat Dams, Causing Copper Deficiency in Suckling Pups

Physiologically relevant iron-copper interactions have been frequently documented. For example, excess enteral iron inhibits copper absorption in laboratory rodents and humans. Whether this also occurs during pregnancy and lactation, when iron supplementation is frequently recommended, is, however, unknown. Here, the hypothesis that high dietary iron will perturb copper homeostasis in pregnant and lactating dams and their pups was tested. We utilized a rat model of iron-deficiency/iron supplementation during pregnancy and lactation to assess this possibility. Rat dams were fed low-iron diets early in pregnancy, and then switched to one of 5 diets with normal (1×) to high iron (20×) until pups were 14 days old. Subsequently, copper and iron homeostasis, and intestinal copper absorption (by oral, intragastric gavage with ⁶⁴Cu), were assessed. Copper depletion/deficiency occurred in the dams and pups as dietary iron increased, as evidenced by decrements in plasma ceruloplasmin (Cp) and superoxide dismutase 1 (SOD1) activity, depletion of hepatic copper, and liver iron loading. Intestinal copper transport and tissue ⁶⁴Cu accumulation were lower in dams consuming excess iron, and tissue ⁶⁴Cu was also low in suckling pups. In some cases, physiological disturbances were noted when dietary iron was only ~3-fold in excess, while for others, effects were observed when dietary iron was 10–20-fold in excess. Excess enteral iron thus antagonizes the absorption of dietary copper, causing copper depletion in dams and their suckling pups. Low milk copper is a likely explanation for copper depletion in the pups, but experimental proof of this awaits future experimentation.

Nutraceuticals in the Prevention of Neonatal Hypoxia-Ischemia: A Comprehensive Review of their Neuroprotective Properties, Mechanisms of Action and Future Directions

Neonatal hypoxia-ischemia (HI) is a brain injury caused by oxygen deprivation to the brain due to birth asphyxia or reduced cerebral blood perfusion, and it often leads to lifelong limiting sequelae such as cerebral palsy, seizures, or mental retardation. HI remains one of the leading causes of neonatal mortality and morbidity worldwide, and current therapies are limited. Hypothermia has been successful in reducing mortality and some disabilities, but it is only applied to a subset of newborns that meet strict inclusion criteria. Given the unpredictable nature of the obstetric complications that contribute to neonatal HI, prophylactic treatments that prevent, rather than rescue, HI brain injury are emerging as a therapeutic alternative. Nutraceuticals are natural compounds present in the diet or used as dietary supplements that have antioxidant, anti-inflammatory, or antiapoptotic properties. This review summarizes the preclinical in vivo studies, mostly conducted on rodent models, that have investigated the neuroprotective properties of nutraceuticals in preventing and reducing HI-induced brain damage and cognitive impairments. The natural products reviewed include polyphenols, omega-3 fatty acids, vitamins, plant-derived compounds (tanshinones, sulforaphane, and capsaicin), and endogenous compounds (melatonin, carnitine, creatine, and lactate). These nutraceuticals were administered before the damage occurred, either to the mothers as a dietary supplement during pregnancy and/or lactation or to the pups prior to HI induction. To date, very few of these nutritional interventions have been investigated in humans, but we refer to those that have been successful in reducing ischemic stroke in adults. Overall, there is a robust body of preclinical evidence that supports the neuroprotective properties of nutraceuticals, and these may represent a safe and inexpensive nutritional strategy for the prevention of neonatal HI encephalopathy.

Hemoglobin concentration and iron supplement during pregnancy were associated with an increased risk of gestational diabetes mellitus

BACKGROUND

Hemoglobin (Hb) measurement is a conventional test during perinatal visits. Hb concentration is related to iron supplement. However, studies focusing on Hb levels, iron supplement, and pregnancy outcomes are scarce. This study aimed to determine whether Hb levels and iron supplement were associated with the risk of gestational diabetes mellitus (GDM).

METHODS

A running hospital-based cohort was conducted from August, 2011. The demographic data and medical information were collected individually through questionnaires and patient medical records. Multiple linear regression was applied for the association between Hb levels, iron supplement, and blood glucose. Multiple logistic regression was used for evaluating odds ratios between Hb levels, iron supplement, and GDM.

RESULTS

Hb levels during first (T1) and second trimester (T2) of pregnancy were significantly and positively associated with blood glucose and GDM risk. After adjusting for age, prepregnancy body mass index, and other risk factors, pregnant women with Hb ≥ 11 g/dL and iron supplement had higher postprandial blood glucose at 1 hour (Hb ≥ 11 g/dL in T2 and iron supplement in T1: β = 0.860，P = <0.001; Hb ≥ 11 g/dL in T2 and iron supplement in T2: β = 0.960，P < 0.001; Hb ≥ 11 g/dL in T1 and iron supplement in T2: β = 1.133, P = 0.033) and GDM risks (odds ratio [OR] = 1.53, 95% confidence interval [CI]: 1.05-2.24; OR = 1.92, 95% CI: 1.13-3.35; OR = 2.15, 95% CI: 1.07-4.34, respectively), compared with those with Hb < 11 g/dL and without iron supplement.

CONCLUSION

High Hb concentration and iron supplements without anemia increased postprandial blood glucose and risks for GDM. It indicates that pregnant women with good Hb levels should not be advised to take iron supplements during pregnancy.