Serum ferritin thresholds for the diagnosis of iron deficiency in pregnancy: a systematic review

Prevalence of Iron Deficiency Using 3 Definitions Among Women in the US and Canada

Importance

The prevalence of iron deficiency varies widely according to how it is defined.

Objective

To compare the prevalence of iron deficiency among women using 3 different definitions.

Design, Setting, and Participants

The cross-sectional Hemochromatosis and Iron Overload Screening Study (HEIRS; 2000-2006) evaluated the prevalence, determinants, and outcomes of hemochromatosis and other iron-related disorders. Multiethnic, primary care-based screening (2001-2003) was performed at 5 field centers (4 in the US and 1 in Canada). Volunteer women aged 25 years and older were recruited at primary care venues associated with the field centers. Data were analyzed from June to December 2023.

Main Outcomes and Measures

Measures included transferrin saturation, serum ferritin level, and self-reported age, pregnancy, and race and ethnicity. Three iron deficiency definitions were studied: (1) combined transferrin saturation less than 10% and serum ferritin less than 15 ng/mL (HEIRS), (2) serum ferritin less than 15 ng/mL (World Health Organization [WHO]), and (3) serum ferritin less than 25 ng/mL (a threshold for iron-deficient erythropoiesis [IDE]).

Results

Among 62 685 women (mean [SD] age, 49.58 [14.27] years), 1957 women (3.12%) had iron deficiency according to the HEIRS definition, 4659 women (7.43%) had iron deficiency according to the WHO definition, and 9611 women (15.33%) had iron deficiency according to the IDE definition. Among 40 381 women aged 25 to 54 years, 1801 women (4.46%) had iron deficiency according to HEIRS, 4267 women (10.57%) had iron deficiency according to WHO, and 8573 women (21.23%) had iron deficiency according to IDE. Prevalence rates of iron deficiency among 2039 women aged 25 to 44 years who reported pregnancy were 5.44% (111 women) according to HEIRS, 18.05% (368 women) according to WHO, and 36.10% (736 women) according to IDE. Iron deficiency prevalence by the 3 respective definitions increased significantly in each racial and ethnic group and was significantly higher among Black and Hispanic participants than Asian and White participants. The relative iron deficiency prevalence among the 62 685 women increased 2.4-fold (95% CI, 2.3-2.5; P < .001) using the WHO definition and increased 4.9-fold (95% CI, 4.7-5.2; P < .001) using the IDE definition.

Conclusions and Relevance

Three definitions of iron deficiency were associated with significantly different prevalence of iron deficiency in women, regardless of self-reported age, pregnancy, or race and ethnicity. Using higher serum ferritin thresholds to define iron deficiency could lead to diagnosis and treatment of more women with iron deficiency and greater reduction of related morbidity.

Effectiveness of non-pharmacological interventions to prevent anemia in pregnant women: a quantitative systematic review protocol

OBJECTIVE

This review will identify the effectiveness of non-pharmacological interventions in preventing iron deficiency anemia in pregnant women with a normal course of pregnancy.

INTRODUCTION

The global prevalence of anemia among pregnant women is 36.5%, posing risks to women and fetuses. This underscores the need for effective prevention; however, the effectiveness of non-pharmacological approaches in preventing pregnancy anemia remains unclear.

INCLUSION CRITERIA

This review will encompass experimental and quasi-experimental studies on the following approaches to prevent anemia during pregnancy: recommendations for dietary supplements, oral iron supplements (over the counter), provision of supplements to promote iron absorption, participation in anemia prevention education, and provision of information. There will be no restrictions on the duration or frequency of intervention, and longitudinal intervention studies will be included. In studies with a control group, the comparator may be usual care or pharmacological interventions; in studies without, it may involve no intervention, temporal comparisons, or baseline periods without non-pharmacological interventions. Evaluation of hemoglobin, hematocrit, and ferritin will be included as primary outcomes. Low birth weight, preterm birth, amount of blood loss at delivery, small for gestational age, and Apgar scores will be included as secondary outcomes.

METHODS

A search will be conducted in MEDLINE (Ovid), Embase, CINAHL (EBSCOhost), Scopus, Australian New Zealand Clinical Trials Registry, Cochrane Central Register of Controlled Trials, and ICHUSHI-Web. Researchers will screen studies, extract data, assess the quality of studies, and analyze the data in accordance with the JBI guidance for systematic reviews of effectiveness. The Grading of Recommendations, Assessment, Development and Evaluation approach will be used to assess the certainty of the findings.

REVIEW REGISTRATION

PROSPERO CRD42022344155.

Transferrin Saturation, Serum Ferritin, and C-Reactive Protein vs. Serum Ferritin for an optimal Iron Deficiency Diagnosis in Candidates for Bariatric Surgery

INTRODUCTION

Iron has different physiological processes and is regulated by hepcidin that is also an acute phase reactant, which increases with inflammation. Obesity produces a pro-inflammatory state, affecting directly the normal regulation of iron, causing ferritin (FER) deficiency. FER is used as the only indicator of the status of iron in patients with obesity, so the majority of them would be underdiagnosed, leading to a high prevalence of iron deficiency (ID) and anemia. The aim of this study is to evaluate the diagnostic tests: transferrin saturation (TS), FER, and C-reactive protein (CRP) vs. FER with the objective of analyzing the most accurate variable for the diagnosis of ID.

MATERIALS AND METHODS

We present a cross-sectional, analytical, and retrospective study, evaluating the diagnostic tests in 96 patients, to whom two methods were applied for the diagnosis of ID: method 1 (FER < 30 ng/mL) and method 2 divided into 2A (FER < 30 ng/mL), 2B (FER 30-100 ng/mL + CRP ≥ 5 mg/L), 2C (FER 100-300 ng/mL + CRP ≥ 5 mg/L + TS < 20%), and 2D (TS < 20%).

RESULTS

The prevalence of ID obtained using method 1 was 30.2% while 69.8% presented ID using total method 2, confirming an underdiagnosis of 39.6%.

CONCLUSION

The inflammatory state in patients with obesity must be considered in the diagnosis of ID. The use of TS, FER, and CRP has greater validity than the use of serum FER for the diagnosis of ID in patients with obesity.

Effectiveness of Oral Iron Therapy in Anemic Inpatient Pregnant Women: A Single Center Retrospective Cohort Study

Background and aim Oral iron therapy is effective in treating iron deficiency anemia in outpatient pregnant women but has not been studied in inpatient pregnant women. We aimed to evaluate the effect of oral iron therapy versus no therapy during hospitalization on maternal and neonatal outcomes in women with anemia who are hospitalized for pregnancy-related morbidities (i.e., preterm premature rupture of membranes, preterm labor, pre-eclampsia, abnormal placentation, or fetal monitoring). Methods A retrospective, single-center study was conducted in hospitalized pregnant women (2018 to 2020) with inpatient stays of more than three days. The primary outcome was a change in hemoglobin level from admission to delivery in women treated with oral iron compared with those left untreated. Secondary outcomes included the total amount of iron administered before delivery, the time interval from admission to delivery, and neonatal effects. Results Two hundred sixty-three women were admitted, 79 women had anemia, and 29 (36.7%) received at least one dose of oral iron. Baseline patient characteristics were similar between groups. The median (interquartile range) dose of iron in the oral iron group was 1185.0 (477.0, 1874.0) mg. Neither absolute hemoglobin before delivery (control group: 10.0±1.2 g/dL; iron group: 10.1±1.1 g/dL; p=0.774) nor change in hemoglobin from admission to delivery (control group: -0.1±1.1 g/dL vs. iron group: 0.4±1.1 g/dL; p=0.232) differed between groups. Women in the control group had shorter length of stay (LOS) median (IQR) than women in the iron group (control group: 7.1 (5.0, 13.7) days; iron group: 11.4 (7.4, 25.9) days; p=0.03). There were no differences in maternal mode of delivery, though each group had high rates of cesarean delivery (control group: 53.7%; iron group: 72.4%; p=0.181). There were no differences in estimated blood loss at delivery (control group: 559±401; iron group: 662.1±337.4;p=0.264) in either group. Neonatal birthweight (control group: 1.9±0.7 kg; iron group: 1.9±0.7 kg; p=0.901), birth hemoglobin (control group: 16.3±2.2 g/dL; iron group: 16±2.2 g/dL; p=0.569), neonatal intensive care unit (NICU) admission (control group: 93.3%; iron group: 84.8%;p=0.272 ), or neonatal death (control group: 8.9%; iron group: 3%; p=0.394) were not different between groups. Conclusions Oral iron administered to anemic inpatient pregnant women was not associated with higher hemoglobin concentrations before delivery. Lack of standardized iron regimens and short hospital stays may contribute to the inefficacy of oral iron for this inpatient pregnant population. The small sample size and retrospective nature of this study are limiting factors in drawing conclusive evidence from this study.

Iron deficiency anemia among women: An issue of health equity

Iron deficiency is the most common and widespread nutritional deficiency in the world. For women, the risk of iron deficiency and iron deficiency anemia increases due to iron demands during pregnancy and regular iron losses due to menstruation during reproductive years. These interrelated conditions are of public health concern as they are highly prevalent, and the negative consequences such as chronic fatigue, cognitive impairment and poor quality of life are broad and multifaceted. People of low socioeconomic status are at higher risk of iron deficiency due to low intake of expensive iron-rich foods, and decreased access to healthcare. In this review, we applied a health equity lens to describe the current state of care for women with iron deficiency with or without anemia. We have highlighted several structural challenges that span from the laboratory diagnosis, inconsistent screening guidelines, and stigma associated with heavy menstrual bleeding, to treatment barriers.

Factors Associated with Anemia and Iron Deficiency during Pregnancy: A Prospective Observational Study in Japan

Gestational anemia (GA) is a global health concern with a remarkably high prevalence in Japan, which is associated with various maternal and neonatal outcomes. This study aimed to explore whether GA and non-anemic iron deficiency (NAID) during the third trimester is associated with maternal characteristics, nutrient intake, low birth weight (LBW), and preterm birth. Participants were categorized into GA, NAID, and normal groups, based on serum ferritin and hemoglobin levels. Nutrient intake was assessed using the Brief Diet History Questionnaire. Data from 317 pregnant women were analyzed, including 110 (34.7%), 151 (47.6%), and 56 (17.6%) women in the GA, NAID, and normal groups, respectively. Factors associated with GA included being multipara (p < 0.001) and not taking any type of iron supplements in the third trimester (p = 0.043). The normal group had a significantly higher proportion of preterm birth and LBW than the GA and NAID groups. The GA group had a significantly higher energy intake than the normal group (p = 0.044). Overall, energy and micronutrient intake were significantly below the estimated average requirement in the dietary reference intakes for Japanese. Health care professionals need to consider nutritional advice that can prevent GA by focusing on overall micronutrients, not just energy intake.

Anemia, red blood cell transfusion and administration of blood products in obstetrics: a nationwide analysis of more than 6 million cases from 2011-2020

BACKGROUND

The prevalence of anemia is high, especially in obstetrics. There is large evidence, that anemia during pregnancy is associated with increased maternal morbidity and mortality. Anemia and peripartum hemorrhage remain the main causes for transfusion of red blood cells (RBC). Patient Blood Management (PBM) reduces the need for RBC transfusion significantly. The present study retrospectively analyzed the impact and prevalence of anemia and RBC transfusion on pregnant women.

MATERIALS AND METHODS

Data were retrieved from the German Statistical Office on pregnant women who delivered in hospital between January 1st 2011 and December 31st 2020. The prevalence of anemia, peripartum hemorrhage, comorbidities, administration of blood products and complications were analyzed.

RESULTS

A total of 6,356,046 pregnant women were analyzed of whom 78,257 (1.23%) received RBC transfusion (RBC transfusion group) and 6,277,789 (98.77%) did not receive RBC transfusion (non-RBC transfusion group). In all women analyzed anemia rate was 23.74%. The rates of anemia during pregnancy (70.39 vs 23.15%; p<0.0001), postpartum hemorrhage (41.42 vs 4.35%; p<0.0001), hospital length of stay (127.5 vs 87.08 hours; p<0.0001) and single complications were higher in women with RBC transfusion compared to women without RBC transfusion.

DISCUSSION

The prevalence of anemia and the increased risk for RBC transfusion show that there is great potential for effective implementation of PBM in obstetrics. The treatment of anemia during pregnancy and reduction of RBC transfusions will decrease maternal morbidity and mortality.

Intravenous ferric derisomaltose versus oral iron for persistent iron deficient pregnant women: a randomised controlled trial

PURPOSE

To compare the efficacy of intravenous (IV) iron (ferric derisomaltose) with oral iron (ferrous fumarate) in women 14-21 weeks pregnant with persistent iron deficiency (ferritin < 30 µg/L).

METHODS

In a single-centre, open-label, randomised controlled trial at a Danish hospital, women with persistent iron deficiency after routine oral iron treatment were allocated to receive 1000 mg IV iron (single-dose) or 100 mg elemental oral iron daily. Outcomes were assessed during an 18-week follow-up period. The primary endpoint was the proportion of non-anaemic (haemoglobin [Hb] ≥ 11 g/dL) women throughout follow-up. Other outcomes included changes in haematological parameters, patient-reported fatigue, and quality of life (QoL). Safety was assessed by recording adverse events.

RESULTS

From July 2017 to February 2020, 100 women were randomised to IV iron and 101 to oral iron. Throughout follow-up, 91% of women were non-anaemic in the IV iron group compared with 73% in the oral iron group (18% difference [95% confidence interval 0.10-0.25]; p < 0.001). The mean Hb increase was significantly greater with IV iron versus oral iron at Weeks 6 (0.4 versus - 0.2 g/dL; p < 0.001), 12 (0.5 versus 0.1 g/dL; p < 0.001), and 18 (0.8 versus 0.5 g/dL; p = 0.01). Improvements in fatigue and QoL were greater with IV iron versus oral iron at Weeks 3 and 6. The incidence of treatment-related adverse events was comparable between treatment groups.

CONCLUSION

IV iron was superior in preventing anaemia compared with oral iron in pregnant women with persistent iron deficiency; biochemical superiority was accompanied by improved fatigue and QoL.

CLINICAL TRIAL REGISTRATION

European Clinical Trials Database: EudraCT no.: 2017-000776-29 (3 May 2017); ClinicalTrials.gov: NCT03188445 (13 June 2017). The trial protocol has been published: https://dx.doi.org/10.1186%2Fs13063-020-04637-z .

Iron supplements in pregnant women with normal iron status: A systematic review and meta-analysis

INTRODUCTION

Effects of daily iron supplementation in iron replete pregnancy are unclear. This systematic review aimed to assess benefits and harms of oral iron supplements in pregnant women without anemia and iron deficiency.

MATERIAL AND METHODS

We predefined and registered a protocol in PROSPERO (CRD42020186210) and performed the review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. We searched for randomized clinical trials (RCTs) and observational studies comparing daily oral iron supplementation with no iron supplements in non-anemic iron replete pregnant women. Searches were conducted in MEDLINE (by PubMed), EMBASE (by OVID), Cochrane Library, and ClinicalTrials.gov from inception to September 2022 without language restrictions. Two authors independently screened records, extracted data, and assessed risk of bias using the revised Cochrane risk of bias tool (RoB2). One author read full-texts, assessed certainty of evidence by GRADE and conducted meta-analyses using a random-effects model. Primary outcomes included iron deficiency anemia, iron deficiency, hemoglobin >130 g/L, elevated iron status, small for gestational age newborns, low birthweight newborns, preterm birth, and congenital anomalies.

RESULTS

Eight RCTs (2822 women) but no observational studies were eligible for inclusion. Daily oral iron supplementation in pregnancy probably reduces iron deficiency anemia at term (risk ratio [RR]: 0.51, 95% confidence interval [CI]: 0.38-0.70; 4 RCTs, 1670 women; I2  = 13%; moderate-certainty evidence) and the incidence of low birthweight babies (RR: 0.30, 95% CI: 0.13-0.68; 2 RCTs, 361 infants; I2  = 0%; moderate-certainty evidence). In addition, it may reduce iron deficiency at term (RR: 0.74, 95% CI: 0.60-0.92; 4 RCTs, 1663 women; I2  = 58%; low-certainty evidence) and the incidence of small for gestational age babies (RR: 0.39, 95% CI: 0.17-0.86; 1 RCT, 213 infants; I2 not estimable; low-certainty evidence).

CONCLUSIONS

Daily iron supplementation in iron replete non-anemic pregnant women probably reduces the risk of maternal iron deficiency anemia at term and low birthweight.

Prevention and Management of Iron Deficiency/Iron-Deficiency Anemia in Women: An Asian Expert Consensus

The lack of standardized clinical practice impeding the optimal management of iron deficiency (ID) and iron deficiency anemia (IDA) in women is a global concern, particularly in the Asia-Pacific region. The aim of this study was to determine best practices through a Delphi consensus process. In Round 1, panelists were asked to rate their level of agreement with 99 statements across four domains: identification, diagnosis and assessment, prevention, and treatment of ID/IDA in women. In Round 2, panelists reappraised their ratings in view of the collective feedback and responses to Round 1. After two rounds, consensus (≥85% agreement) was reached for 84% of the Delphi statements. Experts agreed on the role of presenting symptoms and risk factors in prompting assessments of anemia and iron status in women. Experts repeatedly called for prevention, recommending preventive iron supplementation for pregnant women irrespective of anemia prevalence levels, and for non-pregnant adult women, adolescent girls, and perimenopausal women living in areas with a high prevalence of anemia. Experts unanimously agreed to prescribing oral ferrous iron as first-line therapy for uncomplicated ID/IDA. The recommendations and clinical pathway algorithms generated should be used to inform clinical practice and standardize the care of women at risk or presenting with ID/IDA in the Asia-Pacific region.

Current concepts in preoperative anemia management in obstetrics

PURPOSE OF REVIEW

The purpose of this article is to provide an overview of currently recommended treatment approaches for anemia during pregnancy, with a special focus on iron deficiency and iron deficiency anemia (IDA).

RECENT FINDINGS

As consistent patient blood management (PBM) guidelines in obstetrics are still lacking, recommendations regarding the timing of anemia screening and the treatment recommendations for iron deficiency and IDA during pregnancy are still controversial. Based on increasing evidence, early screening for anemia and iron deficiency should be recommended at the beginning of each pregnancy. To reduce maternal and fetal burden, any iron deficiency, even without anemia, should be treated as early as possible during pregnancy. While oral iron supplements administered every other day are the standard treatment in the first trimester, the use of intravenous iron supplements is increasingly suggested from the second trimester onwards.

SUMMARY

The treatment of anemia, and more specifically iron deficiency anemia during pregnancy, holds many possibilities for improvement. The fact that the period of risk is known well in advance and thus there is a long optimization phase is per se an ideal prerequisite for the best possible therapy of treatable causes of anemia. Standardization of recommendations and guidelines for screening and treatment of IDA in obstetrics is required for the future. In any case, a multidisciplinary consent is the precondition for a successfully implementation of anemia management in obstetrics to establish an approved algorithm easily enabling detection and treatment of IDA during pregnancy.

Thalassemia and Hemoglobinopathy Screening in Women Attending Antenatal Clinic at a Tertiary Care Center in Uttarakhand, India: A Re-look at the Laboratory Parameters Mandating High-Performance Liquid Chromatography Workup

INTRODUCTION

Thalassemia and hemoglobinopathies are the most common inherited hematological disorders. Of these, β thalassemia is the commonest disorder reported in India, followed by certain hemoglobinopathies encountered in different regions of the country. The data pertaining to the incidence of these disorders in the Uttarakhand region of India are sparse.

AIM AND OBJECTIVES

To ascertain the prevalence and spectrum of thalassemia/hemoglobinopathies amongst antenatal women in Uttarakhand. The study also aimed to analyze the ability of red cell indices in differentiating beta thalassemia trait (BTT) from mild iron deficiency anemia (IDA).

MATERIAL AND METHODS

A total of 460 pregnant women in the first trimester of pregnancy were screened by cation exchange high-performance liquid chromatography. Retention time and proportions of normal/abnormal hemoglobin peaks were documented in all cases. Hemoglobin A2 (HbA2) values of ≥4% were taken as a cut-off for diagnosing BTT. Blood samples were also collected for complete blood counts, reticulocyte counts, and serum ferritin. The ability of the various discriminatory indices to differentiate between IDA and BTT was also assessed.

RESULTS

The prevalence of BTT and hemoglobin D-Punjab trait amongst pregnant women was found to be 2.6% and 0.2%, respectively. RBC count, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) were found to be moderately strong predictors of BTT, with an area under the curve of 0.860, 0.857, and 0.842, respectively, which were comparable to the discriminatory indices found to be most useful in this study.

CONCLUSION

In view of the 2.6% prevalence of BTT in antenatal women in this region of Uttarakhand, a routine screening will be helpful in detecting carriers early in the antenatal period. Careful interpretation of red cell indices is crucial to the distinction between BTT and IDA. Discriminatory indices are reasonably accurate in differentiating BTT from mild iron deficiency, but for practical purposes, MCV and MCH provide equivalent information to identify cases that require further workup.

Population iron status in Canada: results from the Canadian Health Measures Survey 2012-2019

BACKGROUND

In Canada, population iron status estimates are dated (2009-2011) and did not consider the presence of inflammation.

OBJECTIVE

To update iron status estimates in Canada using serum ferritin (SF) and evaluate different correction methods for inflammation based on c-reactive protein (CRP).

METHODS

Data from the Canadian Health Measures Survey cycles 3 to 6 (2012-2019) formed a multi-year, cross-sectional, nationally representative sample (3 to 79 years) (n=21,453). WHO cut-offs for SF and hemoglobin were used to estimate iron deficiency (ID), iron deficiency anemia (IDA), anemia and elevated iron stores. ID was first estimated without considering inflammation. Correction approaches evaluated were: excluding individuals with CRP>5 mg/L; using modified SF cut-offs; and regression correction.

RESULTS

Total population uncorrected prevalence estimates were 7% (95%CI: 6.2, 7.9) ID, 6.1% (95%CI: 5.2, 7.0) anemia and 2.0% (95%CI: 1.6, 2.4) IDA. Uncorrected prevalence of ID was highest among females of reproductive age with 21.3% (95%CI: 17.6, 25.0) and 18.2% (95%CI: 15.4, 21.1) in 14-18y and 19-50y respectively. Corrected ID estimates were higher compared to uncorrected values, independent of the correction approach. Regression correction led to a moderate increase in prevalence to 10.5% for the total population while applying the higher modified SF cut-offs (70μg/L for those over 5y) led to the largest increases in prevalence, to 12.6%. Applying modified cut-offs led to implausibly high ID estimates among those with inflammation. Elevated iron stores were identified in 17.2% (95%CI: 16.2, 18.2) of the population, mostly in adult males.

CONCLUSIONS

Correction methods for estimating population iron status need further research. Considering the fundamental drawbacks of each method, uncorrected and regression corrected estimates provide a reasonable range for ID in the Canadian population. Important sex-based differences in iron status and a public health ID problem of moderate magnitude among females of reproductive age are evident in Canada.

Correlation between serum ferritin in early pregnancy and hypertensive disorders in pregnancy

Objective

To explore the correlation between serum ferritin (SF) in early pregnancy and the risk of hypertensive disorders in pregnancy (HDP).

Method

A retrospective cohort study was conducted on 43,421 pregnant women with singleton pregnancies who underwent antenatal checkups at Fujian Provincial Maternal and Child Health Hospital from January 2018 to December 2020. Based on pregnancy records, women were classified as non-hypertensive, having gestational hypertension, preeclampsia and preeclampsia with severe features according to the degree of the disease. General baseline data, and SF levels in the early (up to 12 gestational weeks) and late (after 28  weeks of gestation) stages of pregnancy were collected. The significance of the characteristic variables was assessed using a random forest algorithm, and the correlation between early pregnancy SF levels and the incidence of HDP was further analyzed using logistics regression adjusted for confounders. A generalized additive model (GAM) was fitted to a smoothed graph of the relationship between early pregnancy SF levels and HDP, and a threshold effect analysis was performed to find the threshold values of early pregnancy SF for iron supplementation therapy.

Result

A total of 30,703 pregnant women were included. There were 1,103 women who were diagnosed with HDP. Of them, 418 had gestational hypertension, 12 had chronic hypertension without SPE, 332 - preeclampsia and 341 women had preeclampsia with severe features. Levels of SF in early and late pregnancy were significantly higher (p < 0.001) in women with HDP compared to non-hypertensive women and the difference was more pronounced in early pregnancy. The random forest algorithm showed that early pregnancy SF was more effective in predicting HDP compared to late pregnancy SF levels and was also an independent risk factor for HDP (adjusted odds ratio (AOR) = 1.07, 95% CI [1.05,1.09]) after correction for confounding factors. Early pregnancy SF >64.22  mg/l was associated with higher risk of developing hypertensive disorders.

Conclusion

Risk of pregnancy-related hypertensive disorders increases with increasing early pregnancy SF levels. SF levels may therefore be used to further develop guidelines for iron supplementation therapy in pregnant women.

The incidence, complications, and treatment of iron deficiency in pregnancy

Iron deficiency and/or iron deficiency anemia (IDA) complicate nearly 50% of pregnancies globally, negatively impacting both maternal and fetal outcomes. Iron deficiency can cause a range of symptoms that range from aggravating to debilitating including fatigue, poor quality of life, pagophagia, and restless leg syndrome. Iron deficiency and IDA are also associated with maternal complications including preterm labor, increased rates of cesarean delivery, postpartum hemorrhage, and maternal death. Fetal complications include increased rates of low birth weight and small for gestational age newborns. Prenatal maternal anemia has also been associated with autism spectrum disorders in the neonate, although causation is not established. Deficiency in the newborn is associated with compromised memory, processing, and bonding, with some of these deficits persisting into adulthood. Despite the prevalence and consequences associated with iron deficiency in pregnancy, data show that it is routinely undertreated. Due to the physiologic changes of pregnancy, all pregnant individuals should receive oral iron supplementation. However, the bioavailability of oral iron is poor and it is often ineffective at preventing and treating iron deficiency. Likewise, it frequently causes gastrointestinal symptoms that can worsen the quality of life in pregnancy. Intravenous iron formulations administered in a single or multiple dose series are now available. There is increasing data suggesting that newer intravenous formulations are safe and effective in the second and third trimesters and should be strongly considered in pregnant individuals without optimal response to oral iron repletion.

Anemia in Pregnancy: A knowledge, Attitude and Practice Survey Amongst Obstetricians and Gynaecologists in India

Background

Anemia continues to affect one-third of the global population and is one of the most common reasons for large-scale morbidity and mortality especially among women. The importance of iron-rich diet has always been the backbone of preventing iron deficiency anemia (IDA) in vulnerable age groups followed by oral iron therapy and parenteral iron therapy as the next options in management of iron deficiency.

Objective

Objective of this survey was to assess the knowledge, attitude and practices of obstetricians and gynaecologists relevant to anemia in pregnancy and identify the practice gaps in management of anemia in pregnancy.

Methods

This was a knowledge, attitude and practice (KAP) survey involving obstetricians and gynaecologists (ObGyns) across India. A validated questionnaire of twenty questions was used to assess knowledge, attitude and practice about anemia and its management. Results were expressed as percentages.

Results

1974 ObGyns participated in the survey. 88.7% ObGyns screen anemia in first trimester, 53.7% ObGyns perform CBC along with RBC indices. Majority of ObGyns estimate Hb thrice during antenatal period. 50% ObGyns do not consider thalassemia screening routinely and deworming regularly. 92.4% ObGyns believe that iron supplementation is required even if Hb > 11 g/dL. Majority of them prefer low-dose iron therapy, 59.9% prefer to use 100 mg oral iron daily. Almost half of ObGyns prefer to change iron salt when patients do not respond, instead of escalating to injectable iron. Interestingly 52% ObGyns evaluate serum ferritin before starting intravenous iron therapy. 43.5% perform Hb estimation as early as 2 weeks after IV iron therapy. Majority (82.2%) of ObGyns prefer blood transfusion as a treatment of choice when Hb < 5 g/dl at 34 weeks gestation. Only 40.5% of participants are aware of the exact cut-off for diagnosing postpartum anemia. Majority of the ObGyns are aware of the iron prophylaxis in postpartum period till 3-6 months. More than 90% ObGyns consider intravenous iron for severe anemia of postpartum period.

Conclusion

The present KAP survey highlights the observation, perception and the practicing behaviour of obstetricians and gynaecologists on anemia in pregnancy and identifies practice gaps in anemia management.

Non-iron Deficiency Anemia in Rural Indian Women: A Cross-Sectional Study

Introduction

Anemia is an important public health concern, affecting almost 25% of the global population. In India, these statistics are even more worrisome with more than half of the children, non-pregnant and pregnant women being affected by the disease. Though the major cause of anemia is iron deficiency, other causes cannot be neglected considering the magnitude of the problem. The present study was designed to estimate the prevalence of non-iron deficiency anemia (NIDA) in Devbhoomi Dwarka District of Gujarat.

Methods

For this cross-sectional study, total of 258 mothers (antenatal and postnatal) were enrolled from 27 primary health centers. Apart from demographic details and obstetric history, hemoglobin and ferritin levels were measured from the participant’s blood after obtaining consent. Clinical information such as the history of recent illness and fever were also noted through questionnaires. Prevalence was anemia was calculated using a standard threshold of blood hemoglobin and NIDM was defined using ferritin levels.

Results

As per hemoglobin levels, anemia was present in 65.9% of the mothers, which was relatively higher in antenatal women (90%) as compared to postnatal women (57%). Ferritin levels showed that out of this total anemic mothers, 61.8% (105/258) have normal ferritin levels indicating the presence of non-iron deficiency. Trimester-wise analysis of anemia in AN showed that NIDM prevalence increases with increasing trimester in contrast to IDA where a considerable reduction was found with iron supplementation.

Conclusion

The study indicated that two out of every three women were anemic and only one out of four were anemic with depleted iron storage. These findings have important policy implications as in India the anemia control programs address only iron deficiency anemia and not NIDA. The development of a framework for diagnosis and appropriate treatment can be recommended for integration into national guidelines.

Identification of Serum Ferritin-Specific Nanobodies and Development towards a Diagnostic Immunoassay

Serum ferritin (SF) is an iron-rich protein tightly connected with iron homeostasis, and the variations are frequently observed in diseased states, including iron-deficiency anemia, inflammation, liver disease, and tumors, which renders SF level an indicator of potential malignancies in clinical practice. Nanobodies (Nbs) have been widely explored and developed into theranostic reagents. Surprisingly, no reports stated the identification of anti-SF Nbs, nor the potential of such Nbs as a diagnostic tool. In this study, we generated SF-specific Nbs and provided novel clinical diagnostic approaches to develop an immunoassay. An immune library was constructed after immunizing an alpaca with SF, and five Nbs specifically targeting human SF were retrieved. The obtained Nbs exhibited robust properties including high stability, affinity, and specificity. Then, an ELISA-based test using a heterologous Nb-pair was developed. The calibration curve demonstrated a linear range of SF between 9.0 to 1100 ng/mL, and a limit of detection (LOD) of 1.01 ng/mL. The detecting recovery and coefficient variation (CV) were determined by spiking different concentrations of SF into the serum sample, to verify the successful application of our selected Nbs for SF monitoring. In general, this study generated SF-specific Nbs and demonstrated their potential as diagnostic immunoassay tools.

Trends in ferritin measurements in children and adolescents: A Finnish 9-year observational study

Aim

A lack of stored iron, indicated by low serum ferritin, has been associated with various clinical symptoms. There are no longitudinal data on the frequency of ferritin measurements in children and adolescents.

Methods

A total of 2834 children aged <18 years with serum ferritin and other anaemia‐related blood parameters taken during an outpatient visit between 2012 and 2019 were investigated. Patients with acute infections were excluded. Nationwide temporal and regional variations and correlations with public information searches through Google were analysed.

Results

A significant increase in the frequency of ferritin measurements was seen starting in 2018, with a 47‐fold rise in 2019 compared to 2012. A simultaneous escalation in Google Search activity was seen. Deficiency of stored iron was relatively common: 21.6% of children with normal haemoglobin and 14.9% of non‐anaemic children with normal red cell indices exhibited ferritin levels below 15 μg/L.

Conclusion

Ferritin measurement has increased greatly among children and adolescents. Our results suggest that public interest and popular trends can significantly influence health care practices. This calls for further investigation into the causes and consequences of such a phenomenon. Prospective randomised intervention studies are needed to evaluate the utility of iron supplementation in patients with low iron storage levels.

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.

Iron status and inflammation in women of reproductive age: A population-based biomarker survey and clinical study

BACKGROUND

Women of reproductive age (WRA) are at increased risk for anemia and iron deficiency. However, there is limited population-level data in India, which could help inform evidence-based recommendations and policy.

AIMS

To conduct a population-based biomarker survey of anemia, iron deficiency, and inflammation in WRA in Southern India.

METHODS

Participants were WRA (15-40 y) who were not pregnant or lactating. Blood samples (n = 979) were collected and analyzed for hemoglobin (Hb), serum ferritin (SF), soluble transferrin receptor (sTfR), C-reactive protein (CRP), and alpha-1 acid glycoprotein (AGP). Anemia and severe anemia were defined as Hb < 12.0 and < 8.0 g/dL. Serum ferritin was adjusted for inflammation using BRINDA methods. Iron deficiency was defined as SF <15.0 μg/L, iron insufficiency was defined as SF < 20.0 and < 25.0 μg/L, and iron deficiency anemia was defined as Hb < 12.0 g/dL and SF < 15.0 μg/L. Inflammation was defined as CRP > 5.0 mg/L or AGP > 1.0 g/L. Restricted cubic spline regression models were also used to determine if alternative SF thresholds should be used t to classify iron deficiency.

RESULTS

A total of 41.5% of WRA had anemia, and 3.0% had severe anemia. Findings from spline analyses suggested a SF cut-off of < 15.0 μg/L, consistent with conventional cut-offs for iron deficiency. 46.3% of WRA had SF < 15.0 μg/L (BRINDA-adjusted: 61.5%), 55.0% had SF < 20.0 μg/L (72.7%), 61.8% had SF < 25.0 μg/L (81.0%), and 30.0% had IDA (34.5%). 17.3% of WRA had CRP > 5.0 mg/L and 22.2% had AGP > 1.0 g/L. The prevalence of ID (rural vs. urban: 49.1% vs. 34.9%; p = 0.0004), iron insufficiency (57.8% vs. 43.8%; p = 0.0005), and IDA (31.8% vs. 22.4%; p = 0.01) were significantly higher in rural areas, although CRP levels were lower and there were no differences in elevated CRP or AGP.

CONCLUSIONS

The burden of anemia and iron deficiency in this population was substantial, and increased after adjusting for inflammation, suggesting potential to benefit from screening and interventions.

REGISTRATION NUMBER

NCT04048330.

Maternal early-pregnancy ferritin and offspring neurodevelopment: A prospective cohort study from gestation to school age

BACKGROUND

Iron plays a role in many key processes in the developing brain. During pregnancy, iron supplementation is widely recommended to prevent and treat iron deficiency; however, the prevalence of iron deficiency and the risk of iron overload vary greatly between populations. Evidence on the role of high levels of maternal ferritin, a storage iron marker during pregnancy in relation to offspring neurodevelopment is lacking.

OBJECTIVE

Our main objective was to examine if maternal ferritin levels during pregnancy are associated with child cognitive and motor abilities.

METHODS

We included Dutch mother-child dyads from the prospective population-based Generation R Study, born in 2002-2006. We compared children whose mothers had high (standard deviation score >+1) or low (standard deviation score <-1) early-pregnancy ferritin to children whose mothers had intermediate ferritin (reference group) using linear regression. Children underwent non-verbal intelligence and language tests at 4-9 years (cognitive abilities), finger-tapping and balancing tests at 8-12 years (motor abilities), and structural magnetic resonance imaging at 8-12 years (brain morphology). Covariates were child age, sex, maternal intelligence quotient estimate, age, body-mass-index, education, parity, smoking and alcohol use.

RESULTS

Of the 2479 mother-child dyads with data on maternal ferritin and at least one child neurodevelopmental outcome, 387 mothers had low (mean = 20.6 µg/L), 1700 intermediate (mean = 64.6 µg/L) and 392 high (mean = 170.3 µg/L) early-pregnancy ferritin. High maternal ferritin was associated with 2.54 points (95% confidence interval -4.16, -0.92) lower child intelligence quotient and 16.02 cm³ (95% confidence interval -30.57, -1.48) smaller brain volume. Results remained similar after excluding mothers with high C-reactive protein. Low maternal ferritin was not associated with child cognitive abilities. Maternal ferritin was unrelated to child motor outcomes.

CONCLUSION

High maternal ferritin during pregnancy was associated with poorer child cognitive abilities and smaller brain volume. Maternal iron status during pregnancy may be associated with offspring neurodevelopment.

The importance of nutrition in pregnancy and lactation: lifelong consequences

Most women in the United States do not meet the recommendations for healthful nutrition and weight before and during pregnancy. Women and providers often ask what a healthy diet for a pregnant woman should look like. The message should be “eat better, not more.” This can be achieved by basing diet on a variety of nutrient-dense, whole foods, including fruits, vegetables, legumes, whole grains, healthy fats with omega-3 fatty acids that include nuts and seeds, and fish, in place of poorer quality highly processed foods. Such a diet embodies nutritional density and is less likely to be accompanied by excessive energy intake than the standard American diet consisting of increased intakes of processed foods, fatty red meat, and sweetened foods and beverages. Women who report “prudent” or “health-conscious” eating patterns before and/or during pregnancy may have fewer pregnancy complications and adverse child health outcomes. Comprehensive nutritional supplementation (multiple micronutrients plus balanced protein energy) among women with inadequate nutrition has been associated with improved birth outcomes, including decreased rates of low birthweight. A diet that severely restricts any macronutrient class should be avoided, specifically the ketogenic diet that lacks carbohydrates, the Paleo diet because of dairy restriction, and any diet characterized by excess saturated fats. User-friendly tools to facilitate a quick evaluation of dietary patterns with clear guidance on how to address dietary inadequacies and embedded support from trained healthcare providers are urgently needed.

Recent evidence has shown that although excessive gestational weight gain predicts adverse perinatal outcomes among women with normal weight, the degree of prepregnancy obesity predicts adverse perinatal outcomes to a greater degree than gestational weight gain among women with obesity. Furthermore, low body mass index and insufficient gestational weight gain are associated with poor perinatal outcomes. Observational data have shown that first-trimester gain is the strongest predictor of adverse outcomes. Interventions beginning in early pregnancy or preconception are needed to prevent downstream complications for mothers and their children. For neonates, human milk provides personalized nutrition and is associated with short- and long-term health benefits for infants and mothers. Eating a healthy diet is a way for lactating mothers to support optimal health for themselves and their infants.

Iron deficiency anemia in pregnancy

PURPOSE OF REVIEW

Anemia in pregnancy is associated with increased maternal and neonatal morbidity. There is increasing awareness amongst obstetricians about the need to screen for iron deficiency anemia (IDA), as well as growing literature on diagnosis and treatment. This review aims to summarize causes, consequences, treatment, and evaluation of IDA in pregnancy.

RECENT FINDINGS

National guidelines provide varying guidance on diagnosis and treatment of IDA in pregnancy. Serum ferritin is a helpful adjunct for the diagnosis of IDA. Oral iron remains an option for treatment; absorption is improved with every other day dosing and is effective for patients able to tolerate. Emerging studies on modern generations of intravenous (IV) iron demonstrate shorter infusion times and improved safety profiles. Notably, recent UK guidelines provide consideration for universal IV iron supplementation for treatment of anemia beyond 34 weeks of pregnancy.

SUMMARY

Iron, in dietary, oral, and IV forms, has been found effective in resolving anemia in pregnancy. Pregnant people with IDA in the third trimester are more likely to benefit from IV iron. Future studies designed and powered to assess maternal and perinatal morbidity indicators and blood transfusion rates can strengthen recommendations.

Review of Dietary Recommendations for Twin Pregnancy: Does Nutrition Science Keep Up with the Growing Incidence of Multiple Gestations?

Recommendations for nutrition and the use of dietary supplements for pregnant women are updated on regular basis but it remains to be seen to what extent they may be applicable in twin pregnancies. The aim of this narrative review is to present the current state of knowledge about the energy and nutrient demand in twin pregnancy. There is general consensus in literature that the energy demand is higher than in a singleton pregnancy, but there is a lack of position statements from scientific societies on specific energy intake that is required. In turn, recommended maternal weight gain, which favors the normal weight of the neonate, has been determined. There is even a larger knowledge gap when it comes to vitamins and minerals, the body stores of which are theoretically used up faster. The greatest number of studies so far focused on vitamin D, and most of them concluded that its concentration in maternal blood is lower in twin as compared to singleton pregnancy. Few randomized studies focus on iron supplementation and there are no other studies that would assess dietary interventions. In light of a growing incidence of multiple pregnancies, more studies are necessary to establish the nutritional demands of the mother and the course of action for adequate supplementation.

Hemoglobin Concentration during Early Pregnancy as an Accurate Predictor of Anemia during Late Pregnancy

It is undetermined which blood variables related to iron storage during the first trimester of pregnancy could efficiently predict anemia occurring during the third trimester. Red blood cell count (RBC), hemoglobin concentration, hematocrit, ferritin, iron, and total iron binding capacity (TIBC) were assessed longitudinally during the first, second, and third trimesters of 231 healthy Japanese women. None of the patients had anemia in the first trimester and none used iron supplementation before the second trimester blood test. Anemia was defined as hemoglobin (Hb) < 11 g/dL for the first trimester and Hb < 10.0 g/dL for the third trimester. Forty-seven (20%) women developed anemia in the third trimester. The first trimester RBC, Hb, hematocrit, and ferritin levels were significantly lower in women with third-trimester anemia than those without anemia. The first trimester hemoglobin level exhibited a greater area under the curve of the receiver operating characteristic curve for prediction of the third trimester anemia than other blood variables; the optimal cut-off (12.6 g/dL) of hemoglobin yielded a sensitivity of 83% (39/47). First trimester hemoglobin levels were significantly better predictors of anemia during the third trimester than the indices of iron storage, including serum iron, ferritin, and TIBC levels.

Maternal first trimester iron status and its association with obstetric and perinatal outcomes

PURPOSE

To assess the following in singleton pregnant women: (1) associations between first trimester iron deficiency and obstetric and perinatal outcomes, (2) overall first trimester iron status and (3) post-treatment iron status after intensified iron supplementation.

METHODS

A prospective cohort study was conducted with linkage of first trimester hemoglobin and plasma ferritin with obstetric and perinatal data from a hospital database. Blood sample data were obtained from a Danish University Hospital. The cohort was divided into groups according to ferritin and hemoglobin: (1) iron-deficient anemic (ferritin < 30 ng/mL and Hb < 110 g/L), (2) iron-deficient non-anemic (ferritin < 30 ng/mL and Hb ≥ 110 g/L), and (3) iron-replete non-anemic (ferritin 30-200 ng/mL and Hb ≥ 110 g/L). Obstetric and perinatal outcomes in each iron-deficient group were compared to the iron-replete non-anemic group using multivariable logistic regression. The effect of 4 weeks intensified iron supplementation on hemoglobin and ferritin was assessed by groupwise comparisons.

RESULTS

The cohort comprised 5763 singleton pregnant women, of which 14.2% had non-anemic iron deficiency, and 1.2% had iron-deficiency anemia. Compared to iron-replete non-anemic women, iron-deficient anemic women had a higher risk of gestational diabetes (aOR 3.8, 95% CI 1.4-9.0), and iron-deficient non-anemic women had a higher risk of stillbirth (aOR 4.0, 95% CI 1.0-14.3). In group 1 and 2, 81.5% and 67.7% remained iron-deficient after intensified iron supplementation.

CONCLUSION

Iron-deficiency anemia was associated with gestational diabetes, and non-anemic iron deficiency with stillbirth, although risk estimates were imprecise due to few events. Iron deficiency was present in 15.4% and often persisted despite 4 weeks intensified iron supplementation.

Preconception Hemoglobin Concentration and Risk of Low Birth Weight and Small-for-Gestational-Age: A Large Prospective Cohort Study in China

Less is known about the impact of maternal preconception anemia on birth outcomes. We aimed to examine associations between preconception hemoglobin (Hb) concentrations with risk of low birth weight (LBW) and small-for-gestational-age (SGA). This study was from a large population-based prospective cohort in China and included 124,725 women with singleton live births delivered at gestational ages of 28–45 weeks who were registered before pregnancy. Maternal Hb concentrations were measured during registration, and other health-related information was recorded prospectively. Logistic regression was used to evaluate the associations between preconception Hb concentrations with risk of LBW and SGA, adjusting for potential confounders. The results showed women with preconception anemia accounted for 22.28%. The incidences of LBW/SGA were 2.37%/6.30% among anemic women, and 2.01%/5.48% among non-anemic women, respectively. Preconception mild anemia increased by 17% (95% confidence interval (CI): 1.06, 1.28) and 14% (95% CI: 1.07, 1.21) the risk for LBW and SGA, while moderate-to-severe anemia had no significant association with LBW and SGA. Compared with the 120–129 g/L group, a U-shaped association was observed between preconception Hb concentrations with LBW and SGA. In conclusion, not only maternal anemia but also elevated Hb concentrations before pregnancy contribute to an increased risk of LBW and SGA.

International collaborative study to evaluate and calibrate two recombinant L chain Ferritin preparations for use as a WHO International Standard

OBJECTIVES

To evaluate and calibrate two candidate preparations for the 4th International Standard for Ferritin (Human, Recombinant) (codes: 19/118 and 19/162) against the 3rd International Standard for Ferritin (Human, Recombinant) (code: 94/572), and three serum commutability samples in an international collaborative study involving 12 laboratories in nine countries.

METHODS

Eleven of the 12 participating laboratories performed Ferritin quantitation using automated assay platforms and one laboratory used a manual ELISA kit.

RESULTS

There was better overall agreement between all laboratories and between assay methods for the potency of preparation 19/118 than for preparation 19/162. The overall geometric mean potency (from all methods) of the candidate 4th International Standard, 19/118, was 10.5 µg/ampoule, with inter-laboratory variability, expressed as % geometric coefficient of variation (GCV), of 4.7%. Accelerated stability studies have predicted both 19/118 and 19/162 to be very stable for long term storage at -20 °C.

CONCLUSIONS

The candidate 4th International Standard for Ferritin (Human, Recombinant) (19/118) has been shown to be immunologically similar to the 3rd International Standard for Ferritin (Human, Recombinant) (94/572). It was recommended to and accepted by the WHO Expert Committee on Biological Standardization that 19/118 be established as the 4th International Standard for Ferritin (Human, Recombinant) with an assigned potency of 10.5 µg/ampoule and expanded uncertainty limits 10.2-10.8 µg/ampoule (95% confidence; k=2.23).

Iron Deficiency Anemia in Pregnancy

Anemia is defined as a low red blood cell count, a low hematocrit, or a low hemoglobin concentration. In pregnancy, a hemoglobin concentration of less than 11.0 g/dL in the first trimester and less than 10.5 or 11.0 g/dL in the second or third trimester (depending on the guideline used) is considered anemia. Anemia is the most common hematologic abnormality in pregnancy. Maternal anemia is associated with adverse fetal, neonatal and childhood outcomes, but causality is not established. Maternal anemia increases the likelihood of transfusion at delivery. Besides hemodilution, iron deficiency is the most common cause of anemia in pregnancy. The American College of Obstetricians and Gynecologists recommends screening for anemia with a complete blood count in the first trimester and again at 24 0/7 to 28 6/7 weeks of gestation. Mild anemia, with a hemoglobin of 10.0 g/dL or higher and a mildly low or normal mean corpuscular volume (MCV) is likely iron deficiency anemia. A trial of oral iron can be both diagnostic and therapeutic. Mild anemia with a very low MCV, macrocytic anemia, moderate anemia (hemoglobin 7.0-9.9 g/dL) or severe anemia (hemoglobin 4.0-6.9 g/dL) requires further investigation. Once a diagnosis of iron deficiency anemia is confirmed, first-line treatment is oral iron. New evidence suggests that intermittent dosing is as effective as daily or twice-daily dosing with fewer side effects. For patients with iron deficiency anemia who cannot tolerate, cannot absorb, or do not respond to oral iron, intravenous iron is preferred. With contemporary formulations, allergic reactions are rare.

Physiological and metabolic adaptations in pregnancy: importance of trimester-specific reference intervals to investigate maternal health and complications

Diagnosis, prognostication, and monitoring of maternal health throughout pregnancy relies on laboratory testing, including but not limited to key markers of thyroid, hepatic, cardiac, hematology, and renal function. Dynamic physiological processes during gestation significantly influence the maternal biochemistry that supports both the mother and fetus. Resultant changes in blood biochemistry alter the expected values of common laboratory tests. However, the importance of pregnancy-specific reference intervals for laboratory test result interpretation and appropriate monitoring of maternal health and complications is underappreciated. Most clinical laboratories continue to use non-pregnant adult reference intervals for laboratory test interpretation in pregnancy. The current review summarizes and critically evaluates the available literature regarding physiological and metabolic adaptations in pregnancy and their influence on common biomarkers of health and disease. The main laboratory parameters discussed include thyroid, hepatic, metabolic, renal, hematology, inflammatory, and cardiac markers. Considering the available data, further studies are urgently needed to establish trimester-specific reference intervals in healthy pregnant women on updated analytical platforms. Without such data, the standard of clinical laboratory service in pregnancy remains compromised and affects the quality of maternal-fetal healthcare.

Iron deficiency during the first 1000 days of life: are we doing enough to protect the developing brain?

Iron is essential for the functioning of all cells and organs, most critically for the developing brain in the fundamental neuronal processes of myelination, energy and neurotransmitter metabolism. Iron deficiency, especially in the first 1000 days of life, can result in long-lasting, irreversible deficits in cognition, motor function and behaviour. Pregnant women, infants and young children are most vulnerable to iron deficiency, due to their high requirements to support growth and development, coupled with a frequently inadequate dietary supply. An unrecognised problem is that even if iron intake is adequate, common pregnancy-related and lifestyle factors can affect maternal-fetal iron supply in utero, resulting in an increased risk of deficiency for the mother and her fetus. Although preterm birth, gestational diabetes mellitus and intrauterine growth restriction are known risk factors, more recent evidence suggests that maternal obesity and delivery by caesarean section further increase the risk of iron deficiency in the newborn infant, which can persist into early childhood. Despite the considerable threat that early-life iron deficiency poses to long-term neurological development, life chances and a country's overall social and economic progress, strategies to tackle the issue are non-existent, too limited or totally inappropriate. Prevention strategies, focused on improving the health and nutritional status of women of reproductive age are required. Delayed cord clamping should be considered a priority. Better screening strategies to enable the early detection of iron deficiency during pregnancy and early-life should be prioritised, with intervention strategies to protect maternal health and the developing brain.

Parity-based assessment of anemia and iron deficiency in pregnant women

OBJECTIVE

This study aimed to separately evaluate the prevalence of anemia and iron deficiency in nulliparous and multiparous women.

MATERIALS AND METHODS

We retrospectively examined data of women who delivered in our clinic from January 2016 to December 2018. Inclusion criteria were delivery occurring at ≥36 weeks and singleton pregnancy. Pregnant women with severe medical disorders were excluded. We estimated complete blood count (CBC) and serum ferritin (SF) in the first trimester and only CBC in the late second trimester. Data of nulliparas and multiparas were analyzed separately. Statistically significance was set at p < 0.05.

RESULTS

Totally, 481 nulliparas and 603 and multiparas were enrolled. Mean hemoglobin values in the first trimester were 12.6 ± 1.0 and 12.4 ± 1.0 g/dl (p < 0.001), while median SF values were 42.7 (12.2, 108.2) and 27.7 (8.0, 72.6) ng/ml (p < 0.001) in nulliparas and multiparas, respectively. Hemoglobin in the late second trimester was 11.2 ± 0.9 and 10.7 ± 1.0 g/dl (p < 0.001) in nulliparas and multiparas, respectively. Low ferritin levels (SF < 12 ng/ml) were more frequently found in multiparas than in nulliparas (111/603 vs. 46/481, p < 0.001, Odds ratio [OR] = 2.13). Anemia in the first trimester (hemoglobin<11.0 g/dl) was found in 3.5% (17/481) and 8.8% (53/603) (p < 0.001; OR, 2.63), while that in late second trimester (hemoglobin<10.5) was observed in 21.0% (101/481) and 36.3% (219/603) (p < 0.001, OR = 2.15) nulliparas and multiparas, respectively. Non-anemic women (hemoglobin level ≥11.0) with low ferritin levels (SF < 12 ng/ml) in the first trimester showed higher rate of anemia development in the second trimester than those with both normal hemoglobin and ferritin levels, irrespective of parity (51.3% [19/37] vs. 16.2% [69/427], p < 0.001 in nulliparas and 76.9% [60/78] vs. 26.5% [125/472], p < 0.001 in multiparas].

CONCLUSION

Anemia and low SF levels occurred more commonly in multiparous than in nulliparas. Further, low SF was a risk factor for anemia development in later pregnancy.

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.

Inflammatory biomarkers in pregnant women with COVID-19: a retrospective cohort study

Coronavirus disease 2019 (COVID-19) is a pandemic viral disease affecting also obstetric patients and uncertainties exist about the prognostic role of inflammatory biomarkers and hemocytometry values in patients with this infection. To clarify that, we have assessed the values of several inflammatory biomarkers and hemocytometry variables in a cohort of obstetric patients hospitalized with COVID-19 and we have correlated the values at admission with the need of oxygen supplementation during the hospitalization. Overall, among 62 (27.3%) pregnant women and 165 (72.7%) postpartum women, 21 (9.2%) patients received oxygen supplementation and 2 (0.9%) required admission to intensive care unit but none died. During hospitalization leukocytes (p < 0.001), neutrophils (p < 0.001), neutrophils to lymphocytes ratio (p < 0.001) and C reactive protein (p < 0.001) decreased significantly, whereas lymphocytes (p < 0.001), platelets (p < 0.001) and ferritin (p = 0.001) increased. Lymphocyte values at admission were correlated with oxygen need, with a 26% higher risk of oxygen supplementation for each 1000 cells decreases. Overall, in obstetric patients hospitalized with COVID-19, C reactive protein is the inflammatory biomarker that better mirrors the course of the disease whereas D-dimer or ferritin are not reliable predictors of poor outcome. Care to the need of oxygen supplementation should be reserved to patients with reduced lymphocyte values at admission.

Serum Erythroferrone During Pregnancy Is Related to Erythropoietin but Does Not Predict the Risk of Anemia

BACKGROUND

Maintaining adequate iron status during pregnancy is important for the mother and her developing fetus. Iron homeostasis is influenced by 3 regulatory hormones: erythropoietin (EPO), hepcidin, and erythroferrone (ERFE). To date, normative data on ERFE across pregnancy and its relations to other hormones and iron status indicators are limited.

OBJECTIVES

The objective of this study was to characterize maternal ERFE across pregnancy and at delivery and evaluate the utility of hepcidin, ERFE, and EPO in identifying women with increased iron needs.

METHODS

ERFE was measured in extant serum samples collected from 2 longitudinal cohorts composed of women carrying multiple fetuses (n = 79) and pregnant adolescents (n = 218) at midgestation (∼26 wk) and delivery (∼39 wk). Receiver operating characteristic curves were generated to characterize the predictive ability of serum ERFE, hepcidin, and EPO and their ratios to identify women at increased risk of iron deficiency and anemia.

RESULTS

In these pregnant women, mean ERFE was 0.48 ng/mL at both ∼25 wk of gestation and at delivery. ERFE was positively associated with EPO at midgestation (β = 0.14, P = 0.002, n = 202) and delivery (β = 0.12, P < 0.001, n = 225) but was not significantly associated with maternal hepcidin at any time point surveyed. Of all hormones measured at midgestation and delivery, EPO was best able to identify women with anemia (AUC: 0.86 and 0.75, respectively) and depleted iron stores (AUC: 0.77 and 0.84), whereas the hepcidin-to-EPO ratio was best able to identify women with iron deficiency anemia (AUC: 0.85 and 0.84).

CONCLUSIONS

Maternal ERFE was significantly associated with EPO but was not able to identify women with gestational iron deficiency. At term, the hepcidin-to-EPO ratio, an index that accounts for both iron status and erythropoietic demand, and EPO were the strongest indicators of maternal iron deficiency and anemia. This trial was registered at clinicaltrials.gov as NCT04517734 (https://clinicaltrials.gov/ct2/show/NCT04517734).

Iron, iodine and vitamin D deficiencies during pregnancy: epidemiology, risk factors and developmental impacts

Micronutrient deficiency persists throughout the world, and although the burden is higher in low-resource settings, it is also prevalent in wealthy countries, a phenomenon termed 'hidden hunger'. Due to their high requirements for vitamins and minerals relative to their energy intake, young women and children are particularly vulnerable to hidden hunger. As they share several risk factors and impact on overlapping outcomes, we consider how deficiency of iron, iodine and vitamin D can have profound impacts on perinatal health and infant development. We review the epidemiology of these micronutrient deficiencies during pregnancy, including social, environmental and dietary risk factors. We identify the main challenges in defining nutritional status of these nutrients using validated diagnostic criteria linked with meaningful clinical outcomes. Public health strategies are urgently required to improve the overall health and nutritional status of women of reproductive age. Obesity prevention and early detection of malnutrition with standardised screening methods would detect pregnant women at increased risk of iron deficiency. Development of sensitive, individual biomarkers of iodine status is required to protect maternal health and fetal/infant brain development. Risk assessments of vitamin D requirements during pregnancy need to be revisited from the perspective of fetal and neonatal requirements. International consensus on standardised approaches to micronutrient assessment, analysis and reporting as well as sensitive, clinically validated infant and child neuro-behavioural outcomes will enable progression of useful observational and intervention studies.

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.

Prediction of anemia at delivery

We aimed to assess risk factors for anemia at delivery by conducting a secondary analysis of a prospective cohort study database including 1527 women who delivered vaginally ≥ 36 gestational weeks. Anemia (Hemoglobin (Hb) < 10.5 g/dL) was assessed at delivery. A complete blood count results during pregnancy as well as maternal and obstetrical characteristics were collected. The primary endpoint was to determine the Hb cutoff between 24 and 30 gestational weeks that is predictive of anemia at delivery by using the area under the curve (AUC) of the receiver operating characteristic curve. Independent risk factors for anemia at delivery were assessed using stepwise multivariable logistic regression. Hb and infrequent iron supplement treatment were independent risk factors for anemia at delivery (OR 0.3 95%CI [0.2–0.4] and OR 2.4 95%CI [1.2–4.8], respectively; C statistics 83%). Hb 10.6 g/dL was an accurate cutoff to predict anemia at delivery (AUC 80% 95%CI 75–84%; sensitivity 75% and specificity 74%). Iron supplement was beneficial to prevent anemia regardless of Hb value. Altogether, Hb should be routinely tested between 24 and 30 gestational weeks to screen for anemia. A flow chart for anemia screening and treatment during pregnancy is proposed in the manuscript.

Trial registration: ClinicalTrials.gov Identifier: NCT02434653.

Functional reference limits: a case study of serum ferritin

Reference intervals depend on the distribution of results within a reference population and can be influenced by subclinical disease. Functional reference limits present an opportunity to derive clinically relevant reference limits from routinely collected data sources, which consist of mixed populations of unhealthy and healthy groups. Serum ferritin is a good example of the utility of functional reference limits. Several studies have identified clinically relevant reference limits through examining the relationship between serum ferritin and erythrocyte parameters. These ferritin functional limits often represent the inflection point at which erythrocyte parameters change significantly. Comparison of ferritin functional reference limits with those based on population distributional reference limits reveals that the lower reference limit may fall below the point at which patients become clinically unwell. Functional reference limits may be considered for any biomarker that exhibits a correlated relationship with other biomarkers.

Iron deficiency without anaemia: a diagnosis that matters

Iron deficiency anaemia (IDA) currently affects 1.2 billion people and iron deficiency without anaemia (IDWA) is at least twice as common. IDWA is poorly recognised by clinicians despite its high prevalence, probably because of suboptimal screening recommendations. Diagnosing IDWA relies on a combination of tests, including haemoglobin and ferritin levels, as well as transferrin saturation. Although the causes of iron deficiency may sometimes be obvious, many tend to be overlooked. Iron sufficiency throughout pregnancy is necessary for maternal and foetal health. Preoperative IDWA must be corrected to reduce the risk of transfusion and postoperative anaemia. Oral iron is the first-line treatment for managing IDWA; however, intravenous supplementation should be used in chronic inflammatory conditions and when oral therapy is poorly tolerated or ineffective. This review considers the causes and clinical features of IDWA, calls for greater awareness of the condition, and proposes diagnostic and management algorithms.

Prevalence of anemia and iron deficiency anemia in Chinese pregnant women (IRON WOMEN): a national cross-sectional survey

Background

The current evidence about anemia and iron deficiency anemia (IDA) during pregnancy remains elusive in China. The purpose of this study is to investigate the prevalence of anemia and IDA and their risk factors in Chinese pregnant women.

Methods

A nationwide cross-sectional survey of pregnant women was conducted during their antenatal visits. Using a multi-stage sampling method, 24 hospitals from 16 provinces across China were selected. Structured questionnaires were administered to collect information from participants and to extract clinical data from electronic medical records. Mixed-effects logistic regression models were performed to determine the risk factors associated with anemia and IDA.

Results

In total, 12,403 pregnant women were enrolled, including 1018 (8.2%) at the first trimester, 3487 (28.1%) at the second, and 7898 (63.7%) at the third. Overall, 19.8% of women were diagnosed with anemia and 13.9% were diagnosed with IDA. The prevalence of anemia and IDA varied among regions and increased by gestational month, peaking at the eighth gestational month (24.0% for anemia and 17.8% for IDA). Pregnant women at advanced stage of gestation, non-local residents, multiple gestations, multiparity, pre-pregnancy underweight, and those experiencing severe nausea or vomiting during pregnancy, were associated with higher risks of anemia and IDA.

Conclusions

The prevalence of anemia and IDA during pregnancy are similar to those from developed countries and vary across regions in China.

Population-based study of serum ferritin in early pregnancy and adverse perinatal outcomes

BACKGROUND

Chronic placental inflammation is associated with preterm birth (PTB) and perinatal mortality. Ferritin is often elevated in chronic inflammatory conditions, but prior studies of its relation to PTB were restricted to ferritin measurement within pregnancy, were underpowered to detect rarer outcomes, and did not account for pre-existing maternal inflammatory conditions, such as inflammatory bowel or rheumatological disease.

OBJECTIVES

To evaluate whether an elevated ferritin level prior to pregnancy is associated with major adverse pregnancy outcomes.

METHODS

A population-based cohort study was completed using Ontario, Canada. Included were all Ontarian women with a hospital livebirth or stillbirth at ≥20 weeks' gestation, 2007-2018, and serum haemoglobin and ferritin measured as an outpatient within 120 days before conception. Excluded were women with a diagnosed iron overload disorder or a ferritin concentration <15 µg/L. The main exposure was a pre-pregnancy serum ferritin ≥95th percentile. Study outcomes included PTB < 37 weeks' gestation, including clinician-initiated and spontaneous PTB; PTB < 32 weeks; chorioamnionitis; and perinatal death. Relative risks (RR) and 95% confidence intervals (CI) were calculated for each study outcome, comparing a serum ferritin concentration ≥95th vs <5th percentile (the referent), while adjusting maternal age, residence, haemoglobin concentration, diabetes mellitus, inflammatory bowel disease, illicit drug/tobacco use, chronic kidney disease, chronic hypertension, sickle-cell disease or thalassaemia, and rheumatological conditions.

RESULTS

Among 89 847 births, a preconceptional maternal serum ferritin ≥95th (112.0 μg/L) vs <5th (16.9 μg/L) percentile was associated with an adjusted relative risk (aRR) of 1.34 (95% CI 1.15, 1.57) for PTB, including spontaneous and clinician-initiated PTB. Results were equivocal for chorioamnionitis (aRR 1.23, 95% CI 0.81, 1.86), and there was no association with perinatal mortality (aRR 0.94, 95% CI 0.55, 1.61).

CONCLUSION

A high preconceptional ferritin concentration is associated with some adverse perinatal outcomes.

Revisiting the basis for haemoglobin screening in pregnancy

PURPOSE OF REVIEW

Anaemia affects up to 50% of pregnancies worldwide, and is associated with maternal and neonatal morbidity and mortality. Prevention and management of anaemia remains a priority. Despite this, there is ongoing debate on the optimal approach to identifying anaemia in pregnant women and the best strategies for prevention and management. The objective of this review is to describe the current landscape of haemoglobin testing in pregnancy in low and high-income countries.

RECENT FINDINGS

Current definitions of anaemia in pregnancy comprise a laboratory threshold of haemoglobin below which treatment is offered. Haemoglobin measurement is not sensitive in detecting iron deficiency - the most common cause of maternal anaemia. Furthermore, these historical thresholds were derived from heterogeneous populations comprising men and women. Women with anaemia in pregnancy are offered iron therapy, without testing for the underlying cause. This may be appropriate in high-income settings, where iron deficiency is the likely cause, but may not address the complex causes of anaemia in other geographical areas.

SUMMARY

Current thresholds of haemoglobin defining anaemia in pregnancy are under review. Further research and policy should focus on optimal strategies to identify women at risk of anaemia from all causes.

A systematic review and meta-analysis of the correlation between maternal and neonatal iron status and haematologic indices

BACKGROUND

Iron deficiency (ID) is the leading single-nutrient deficiency in the world. Anaemia is a common outcome of ID that affects half of pregnancies worldwide with serious consequences for child development. Whether haematologic indices and biomarkers of iron status in pregnant women correlate with those of their neonates is unclear. This systematic review evaluated studies comparing haematologic and iron status indices in pregnant women and their newborns/neonates.

METHODS

We searched MEDLINE, EMBASE, CINAHL, and Web of Science from database inception until March 2020 for primary studies comparing haematologic and iron status indices between women and their newborns up to 48 h after birth. We summarized the results descriptively and calculated pooled correlation coefficients in mothers and newborns/neonates using the Schmidt-Hunter method. The protocol was registered at PROSPERO International Prospective Register of Systematic Reviews (Registration number: CRD42018093094).

FINDINGS

Sixty-five studies were included. Pooled correlation coefficients for biomarkers of iron status in mothers and newborns/neonates were 0.13 (ferritin), 0.42 (hepcidin), 0.30 (serum/plasma iron), 0.09 (transferrin), 0.20 (transferrin saturation), and 0.16 (total iron binding capacity). Pooled correlation coefficients for haematological indices in mothers and newborns/neonates were 0.15 (haemoglobin), 0.15 (haematocrit), 0.25 (mean cell/corpuscular haemoglobin), 0.22 (mean cell/corpuscular volume).

INTERPRETATION

Maternal biomarkers of iron and haematologic status correlate poorly with those in newborns/neonates. These results underscore a need for alternative approaches to estimate foetal/neonatal iron status and haematological indices.

FUNDING

MBO and SLB hold Canada Research Chairs, and grants from the Women and Children's Health Research Institute and Canadian Institutes of Health Research.

Biochemistry of mammalian ferritins in the regulation of cellular iron homeostasis and oxidative responses

Ferritin, an iron-storage protein, regulates cellular iron metabolism and oxidative stress. The ferritin structure is characterized as a spherical cage, inside which large amounts of iron are deposited in a safe, compact and bioavailable form. All ferritins readily catalyze Fe(II) oxidation by peroxides at the ferroxidase center to prevent free Fe(II) from participating in oxygen free radical formation via Fenton chemistry. Thus, ferritin is generally recognized as a cytoprotective stratagem against intracellular oxidative damage The expression of cytosolic ferritins is usually regulated by iron status and oxidative stress at both the transcriptional and post-transcriptional levels. The mechanism of ferritin-mediated iron recycling is far from clarified, though nuclear receptor co-activator 4 (NCOA4) was recently identified as a cargo receptor for ferritin-based lysosomal degradation. Cytosolic ferritins are heteropolymers assembled by H- and L-chains in different proportions. The mitochondrial ferritins are homopolymers and distributed in restricted tissues. They play protective roles in mitochondria where heme- and Fe/S-enzymes are synthesized and high levels of ROS are produced. Genetic ferritin disorders are mainly related to the L-chain mutations, which generally cause severe movement diseases. This review is focused on the biochemistry and function of mammalian intracellular ferritin as the major iron-storage and anti-oxidation protein.

Disordered serum erythroferrone and hepcidin levels as indicators of the spontaneous abortion occurrence during early pregnancy in humans

Spontaneous abortion is a common, detrimental outcome of pregnancy, and can be induced by a variety of factors, including pathophysiological conditions and socioeconomic circumstances. Despite numerous studies examining the aetiology of spontaneous abortion, there is limited understanding of the disordered iron transportation between mother and fetus through the placenta. Recently, erythroferrone (ERFE) was recognized as a novel negative regulator of hepcidin that can elevate nutritional iron absorption and macrophagic iron egress for enhanced erythropoiesis. However, its diagnostic significance in different disease conditions associated with iron remains poorly understood. In the current study, we discovered disordered maternal iron homeostasis in women who had spontaneous abortions during early pregnancy, as characterized by increased serum iron and hepcidin levels, and conversely, reduced serum ERFE levels, compared to healthy control individuals and women with normal pregnancy. Comprehensive statistical analyses revealed the correlation between different variables and pregnancy status, signifying the pronounced diagnostic value of an increased ratio of serum hepcidin and ERFE (HE ratio) in recognizing adverse pregnancy status. In contrast to previous non-selective discrete surrogates, such as iron, hepcidin and ferritin, the HE ratio may otherwise stand for a novel and more representative hallmark for early spontaneous abortion.

Is untargeted iron supplementation harmful when iron deficiency is not the major cause of anaemia? Study protocol for a double-blind, randomised controlled trial among non-pregnant Cambodian women

INTRODUCTION

The WHO recommends daily oral iron supplementation for 12 weeks in women and adolescents where anaemia prevalence is greater than 40%. However, if iron deficiency is not a major cause of anaemia, then, at best, untargeted iron supplementation is a waste of resources; at worst, it could cause harm. Further, different forms of iron with varying bioavailability may present greater risks of harm.

METHODS AND ANALYSIS

A 12-week three-arm, double-blind, randomised controlled supplementation trial was conducted in Cambodia to determine if there is potential harm associated with untargeted iron supplementation. We will recruit and randomise 480 non-pregnant women (ages 18-45 years) to receive one of three interventions: 60 mg elemental iron as ferrous sulfate (the standard, commonly used form), 18 mg ferrous bisglycinate (a highly bioavailable iron amino acid chelate) or placebo. We will measure ferritin concentrations (to evaluate non-inferiority between the two forms of iron), as well as markers of potential harm in blood and stool (faecal calprotectin, gut pathogen abundance and DNA damage) at baseline and 12 weeks. Mixed-effects generalised linear models will be used to assess the effect of iron on ferritin concentration and markers of potential harm at 12 weeks.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the University of British Columbia Clinical Research Ethics Board (H18-02610), the Children's and Women's Health Centre of British Columbia Research Ethics Board (H18-02610) and the National Ethics Committee for Health Research in Cambodia (273-NECHR). Findings will be published in peer-reviewed journals, presented to stakeholders and policymakers globally and shared within participants' communities.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04017598).