Anaemia, pregnancy, and maternal mortality: the problem with globally standardised haemoglobin cutoffs

Variation Patterns of Hemoglobin Levels by Gestational Age during Pregnancy: A Cross-Sectional Analysis of a Multi-Center Retrospective Cohort Study in China

Background: Pregnancy anemia is a global health concern. However, to our knowledge, there still has little consensus on the reference value of hemoglobin levels. Particularly, little evidence from China was accessible in most existing guidelines. Objective: To evaluate hemoglobin levels and anemia prevalence of pregnant women in China and offer evidence for anemia and its reference values in China. Methods: A multi-center retrospective cohort study was conducted among 143,307 singleton pregnant women aged 15–49 at 139 hospitals in China, with hemoglobin concentrations routinely tested at each prenatal visit. Subsequently, a restricted cubic spline was performed to reveal a non-linear variation of hemoglobin concentrations during the gestational week. The Loess model was used to describe the changes in the prevalence of different degrees of anemia with gestational age. Multivariate linear regression model and Logistic regression model were applied to explore influencing factors of gestational changes in hemoglobin level and anemia prevalence, respectively. Results: Hemoglobin varied nonlinearly with gestational age, and the mean hemoglobin levels decreased from 125.75 g/L in the first trimester to 118.71 g/L in the third trimester. By analyzing hemoglobin levels with gestational age and pregnancy period, we proposed new criteria according to 5th percentile hemoglobin concentration in each trimester as a reference for anemia, with 108 g/L, 103 g/L, and 99 g/L, respectively. According to WHO’s criteria, the prevalence of anemia sustainably increased with gestational age, with 6.2% (4083/65,691) in the first trimester, 11.5% (7974/69,184) in the second trimester and 21.9% (12,295/56,042) in the third trimester, respectively. In subsequent analysis, pregnant women in non-urban residents, multiparity, and pre-pregnancy underweight tended to have lower hemoglobin levels. Conclusions: This research, the first large-sample study to present a set of gestational age-specific reference centiles for hemoglobin levels in China, could be used to obtain a better understanding of the overall levels of hemoglobin in Chinese healthy pregnant women and ultimately offer clues for a more precise hemoglobin reference value of anemia in China.

Antepartum and postpartum anemia: a narrative review

Antepartum anemia impacts over a third of pregnant women globally and is associated with major maternal and perinatal morbidity, including peripartum transfusion, maternal death, maternal infection, preterm birth, and neurodevelopmental disorders among offspring. Postpartum anemia impacts up to 80% of women in low-income and rural populations and up to 50% of women in Europe and the United States, and is associated with postpartum depression, fatigue, impaired cognition, and altered maternal-infant bonding. Iron deficiency is the most common cause of maternal anemia because of insufficient maternal iron stores at the start of pregnancy, increased pregnancy-related iron requirements, and iron losses due to blood loss during parturition. Anemic women should undergo testing for iron deficiency; a serum ferritin cutoff level of 30 μg/L is commonly used to diagnose iron deficiency during pregnancy. The first-line treatment of iron deficiency is oral iron. Intravenous iron is a consideration in the following scenarios: a poor or absent response to oral iron, severe anemia (a hemoglobin concentration <80 g/L), rapid treatment for anemia in the third trimester, women at high risk for major bleeding (such as those with placenta accreta), and women for whom red blood cell transfusion is not an option. Given the high prevalence of antepartum and postpartum anemia, anesthesiologists are advised to partner with other maternal health professionals to develop anemia screening and treatment pathways.

Slower response to treatment of iron-deficiency anaemia in pregnant women infected with HIV: a prospective cohort study

OBJECTIVE

Antenatal anaemia is associated with increased peripartum transfusion requirement in South Africa. We studied whether HIV was associated with the response to treatment of iron-deficiency anaemia.

DESIGN

Prospective cohort study.

SETTING

Hospital-based antenatal anaemia clinic in South Africa.

SAMPLE

Equal-sized cohorts of pregnant women testing positive for HIV (HIV+) and testing negative for HIV (HIV-) with iron-deficiency anaemia.

METHODS

Haemoglobin trajectories of women with confirmed iron-deficiency anaemia (ferritin < 50 ng/ml) were estimated from the initiation of iron supplementation using mixed-effects modelling, adjusted for baseline HIV status, ferritin level, maternal and gestational ages and time-varying iron supplementation.

MAIN OUTCOME MEASURES

Haemoglobin trajectories.

RESULTS

Of 469 women enrolled, 51% were HIV+, 90% of whom were on antiretroviral therapy (with a mean CD4+ lymphocyte count of 403 cells/mm³ ). Anaemia diagnoses did not differ by HIV status. A total of 400 women with iron-deficiency anaemia were followed during treatment with oral or intravenous (6%) iron therapy. In multivariable analysis, haemoglobin recovery was 0.10 g/dl per week slower on average in women who were HIV+ versus women who were HIV- (P = 0.001), 0.01 g/dl per week slower in women with higher baseline ferritin (P < 0.001) and 0.06 g/dl per week faster in women who were compliant with oral iron therapy (P = 0.002).

CONCLUSIONS

Compared with women who were HIV-, women who were HIV+ with iron-deficiency anaemia had slower but successful haemoglobin recovery with iron therapy. Earlier effective management of iron deficiency could reduce the incidence of peripartum blood transfusion.

TWEETABLE ABSTRACT

Among pregnant women with iron-deficiency anaemia in South Africa, HIV slows haemoglobin recovery in response to oral iron therapy.

Association between maternal anemia at admission for delivery and adverse perinatal outcomes

BACKGROUND

Maternal anemia is a risk factor for poor pregnancy outcomes and threatens maternal or fetal life. Anemia increases the risk of low birth weight and preterm birth. We aimed to determine the cutoff level of hemoglobin and risk factors for maternal anemia at admission for delivery and investigate the association between maternal anemia and adverse perinatal outcomes in contemporary Taiwanese women.

METHODS

About 32,234 women admitted to the Taipei Chang Gung Memorial Hospital from 2001 to 2016 were enrolled in this retrospective observational cohort study. The prevalence of pre-delivery maternal anemia in Taiwan and the maternal demographic and perinatal outcomes associated with maternal anemia was assessed.

RESULTS

The 10th and 5th percentile hemoglobin levels of the test cohort (2001-2008, n = 15,602) were 10.8 g/dL and 9.9 g/dL, respectively. In the study cohort (2009-2016, n = 13,026), women who were multiparous, who were aged >34 years, with history of cesarean delivery, and with history of uterine fibroids had higher prevalence of anemia. Anemic women were at increased risk of cesarean delivery, primary cesarean delivery, premature rupture of membranes, early preterm birth <34 weeks, having very low birth weight infants (<1,500 g), having large for gestational age infants, and neonatal intensive care center transfer, but at lower risk of having small for gestational age infants.

CONCLUSION

Maternal anemia at delivery is a risk factor for primary cesarean delivery and adverse maternal and neonatal outcomes. Furthermore, we hypothesize that maternal anemia might increase fetoplacental vasculogenesis and angiogenesis as an adaptive response.

Descriptive epidemiology of anaemia among pregnant women initiating antenatal care in rural Northern Ghana

Background

Anaemia in pregnancy is associated with adverse obstetric outcomes. When detected early in pregnancy, it can be treated; however, information on its prevalence and associated factors is limited in rural Ghana.

Aim

The aim of this study was to determine the prevalence and maternal factors associated with anaemia in pregnancy at first antenatal care (ANC) visits.

Setting

The study was conducted in the Navrongo War Memorial Hospital, a secondary referral facility in the Kassena-Nankana district in rural northern Ghana.

Methods

A retrospective analysis of antenatal clinic records of pregnant women collected from January to December 2014. All pregnant women initiating antenatal clinic, who had initial haemoglobin (Hb) levels measured, were included in the study. Logistic regression analyses were carried out to determine factors associated with anaemia at the initiation of ANC.

Results

We analysed data from 506 women with median Hb of 11.1 g/dL (IQR 7.31–13.8). The median gestational age at booking was 14 weeks (5–36 weeks). The prevalence of anaemia was 42.7%, with 95% confidence interval (CI) [38.4–47.1], and was high among teenage mothers (52% [34.9–67.8]), mothers who booked in the third trimester (55% [33.6–74.7]) and grand multiparous women (58% [30.7–81.6]). Factors associated with anaemia included grand multiparity (odds ratio [OR] = 1.94 with 95% CI [1.58–2.46]), booking during the third trimester (OR = 2.06 [1.78–2.21]) and mother who were underweight compared to those with normal weight (OR = 3.17 [1.19–8.32]).

Conclusion

Burden of anaemia in pregnancy is still high in rural northern Ghana. We advocate further strengthening of the primary health care system to improve early access to ANC delivery.

Keywords

anaemia in pregnancy; booking visit; maternal and child health; Navrongo; rural; Ghana.

Effects of lipid-based nutrient supplements or multiple micronutrient supplements compared with iron and folic acid supplements during pregnancy on maternal haemoglobin and iron status

We examined the effect of three types of prenatal supplements containing different amounts of iron on haemoglobin (Hb) and iron status (zinc protoporphyrin [ZPP] and soluble transferrin receptor [sTfR]) in late pregnancy among 1,379 women in rural Malawi. Participants were recruited at ≤20 gestational weeks (gw) and randomly assigned to consume daily (1) 60‐mg iron and folic acid (IFA); (2) 20‐mg iron plus 17 micronutrients in a capsule (MMN); or (3) lipid‐based nutrient supplement (LNS; 118 kcal) with 20‐mg iron plus 21 micronutrients, protein, and fat. We analysed differences between intervention groups in mean Hb, ZPP, and sTfR at 36 gw, and the proportion with anaemia (Hb < 100 g L⁻¹) and iron deficiency (ZPP > 60 μmol mol⁻¹ haem or sTfR > 6 mg L⁻¹) at 36 gw. Women in the IFA group had higher Hb at 36 gw than women in the LNS group (P = 0.030) and higher iron status (lower ZPP and sTfR) than women in both the LNS (P < 0.001 for both ZPP and sTfR) and MMN (P = 0.025 and P = 0.046) groups. Results for anaemia and iron deficiency showed similar trends. Further research is needed to elucidate the appropriate amount of iron to improve Hb and iron status, while improving birth outcomes.

Biomarkers of Nutrition for Development (BOND)-Iron Review

This is the fifth in the series of reviews developed as part of the Biomarkers of Nutrition for Development (BOND) program. The BOND Iron Expert Panel (I-EP) reviewed the extant knowledge regarding iron biology, public health implications, and the relative usefulness of currently available biomarkers of iron status from deficiency to overload. Approaches to assessing intake, including bioavailability, are also covered. The report also covers technical and laboratory considerations for the use of available biomarkers of iron status, and concludes with a description of research priorities along with a brief discussion of new biomarkers with potential for use across the spectrum of activities related to the study of iron in human health.The I-EP concluded that current iron biomarkers are reliable for accurately assessing many aspects of iron nutrition. However, a clear distinction is made between the relative strengths of biomarkers to assess hematological consequences of iron deficiency versus other putative functional outcomes, particularly the relationship between maternal and fetal iron status during pregnancy, birth outcomes, and infant cognitive, motor and emotional development. The I-EP also highlighted the importance of considering the confounding effects of inflammation and infection on the interpretation of iron biomarker results, as well as the impact of life stage. Finally, alternative approaches to the evaluation of the risk for nutritional iron overload at the population level are presented, because the currently designated upper limits for the biomarker generally employed (serum ferritin) may not differentiate between true iron overload and the effects of subclinical inflammation.

Distant and proximate factors associated with maternal near-miss: a nested case-control study in selected public hospitals of Addis Ababa, Ethiopia

Background

Ethiopia is one of the sub-Saharan Africa countries with the highest maternal mortality. Maternal near-misses are more common than deaths and statistically stronger for a comprehensive analysis of the determinants. The study aimed to identify the factors associated with maternal near-miss in selected public hospitals of Addis Ababa, Ethiopia.

Methods

We conducted a nested case-control study in five selected public hospitals of Addis Ababa, Ethiopia from May 1, 2015 to April 30, 2016. Participants were interviewed by well-trained data collectors using pre-tested questionnaire. Medical records were also reviewed to gather relevant information. World Health Organization criteria were used to identify maternal near-miss cases. A total of three controls matched for age and study area was selected for each maternal near-miss case. Bivariate and multivariable conditional logistic regressions were performed using Stata version 13.0.

Results

A total of 216 maternal near-miss cases and 648 controls were included in the study. The main factors associated with maternal near-miss were: history of chronic hypertension (AOR = 10.80,95% CI; 5.16–22.60), rural residency (AOR = 10.60,95% CI;4.59–24.46), history of stillbirth (AOR = 6.03,95% CI;2.09–17.41), no antenatal care attendance (AOR = 5.58,95% CI;1.94–16.07) and history of anemia (AOR = 5.26,95% CI;2.89–9.57).

Conclusions

There is a need for appropriate interventions in order to improve the identified factors. The factors can be modified through a better access to medical and maternity care, scaling up of antenatal care in rural areas, improve in infrastructure to fulfill referral chain from primary level to secondary and tertiary health care levels, and health education to pregnant women.

Point-of-care diagnostics to improve maternal and neonatal health in low-resource settings

Each day, approximately 830 women and 7400 newborns die from complications during pregnancy and childbirth. Improving maternal and neonatal health will require bringing rapid diagnosis and treatment to the point of care in low-resource settings. However, to date there are few diagnostic tools available that can be used at the point of care to detect the leading causes of maternal and neonatal mortality in low-resource settings. Here we review both commercially available diagnostics and technologies that are currently in development to detect the leading causes of maternal and neonatal mortality, highlighting key gaps in development where innovative design could increase access to technology and enable rapid diagnosis at the bedside.

Anemia and pregnancy outcomes: a longitudinal study

OBJECTIVES

To determine the prevalence of anemia at the first antenatal visit and at 32-34 weeks gestational age, and to evaluate perinatal and maternal outcomes.

METHODS

Venous blood samples were obtained for complete blood counts at both study visits. Maternal and perinatal morbidity and mortality were also recorded. The data were analyzed using SPSS (version 23).

RESULTS

Two thousand pregnant women were recruited. The prevalence of anemia was 42.7% (n = 854/2000) at the first antenatal visit. Thirty-five percent had mild anemia and 68.9% had normocytic normochromic anemia. The prevalence of anemia in HIV infected women was higher than that in the noninfected group and 47.2% of the study population (n = 2000) was HIV infected. At the 32-34 weeks visit, hemoglobin (Hb) levels were available for 1433/2000 (71.7%) of the participants. The prevalence of anemia was 28.1% (n = 403/1433); 19.3% had mild anemia and 65.3% had normocytic normochromic anemia. There was a significant difference in Hb levels between that of the first visit and that at 32-34 weeks (42.7% vs. 28.1%; p = .001; 95% CI: 0.11-0.18). There were significant differences in prematurity, birth weight and hypertensive disorders of pregnancy between the anemic and nonanemic groups.

CONCLUSION

The prevalence of anemia decreased from 42.7% (booking) to 28.1% (32 - 34 weeks). Normocytic normochromic anemia was the commonest type of anemia. Attention needs to be focused on detailed investigations to establish the exact cause of anemia.

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

The World Health Organization recommends universal iron supplementation of 30-60 mg/day in pregnancy but coverage is low in most countries. Its efficacy is uncertain, however, and there has been a vigorous debate in the last decade about its safety, particularly in areas with a high burden of malaria and other infectious diseases. We reviewed the evidence on the safety and efficacy of antenatal iron supplementation in low-income countries. We found no evidence that daily supplementation at a dose of 60 mg leads to increased maternal Plasmodium infection risk. On the other hand, recent meta-analyses found that antenatal iron supplementation provides benefits for maternal health (severe anaemia at postpartum, blood transfusion). For neonates, there was a reduced prematurity risk, and only a small or no effect on birth weight. A recent trial showed, however, that benefits of antenatal iron supplementation on maternal and neonatal health vary by maternal iron status, with substantial benefits in iron-deficient women. The benefits of universal iron supplementation are likely to vary with the prevalence of iron deficiency. As a consequence, the balance between benefits and risks is probably more favourable in low-income countries than in high-income countries despite the higher exposure to infectious pathogens.

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

The aim of this review was to understand the landscape of serum ferritin in diagnosing iron deficiency in the aetiology of anaemia in pregnancy. Iron deficiency in pregnancy is a major public health problem leading to the development of anaemia. Reducing the global prevalence of anaemia in women of reproductive age is a 2025 global nutrition target. Bone marrow aspiration is the gold standard test for iron deficiency but requires an invasive procedure; therefore, serum ferritin is the most clinically useful test. We undertook a systematic search of electronic databases and trial registers from inception to January 2016. Studies of iron or micronutrient supplementation in pregnancy with pre‐defined serum ferritin thresholds were included. Two independent reviewers selected studies, extracted data and assessed quality. There were 76 relevant studies mainly of observational study design (57%). The most commonly used thresholds of serum ferritin for the diagnosis of iron deficiency were <12 and <15 ng mL⁻¹ (68%). Most primary studies provided no justification for the choice of serum ferritin threshold used, but 25 studies (33%) used thresholds defined by expert consensus in a guideline development process. There were five studies (7%) using a serum ferritin threshold defining iron deficiency derived from primary studies of bone marrow aspiration. Unified international thresholds of iron deficiency for women throughout pregnancy are required for accurate assessments of the global disease burden and for evaluating effectiveness of interventions addressing this problem.

Iron deficiency anemia in pregnancy

Anemia is the most frequent derailment of physiology in the world throughout the life of a woman. It is a serious condition in countries that are industrialized and in countries with poor resources. The main purpose of this manuscript is to give the right concern of anemia in pregnancy. The most common causes of anemia are poor nutrition, iron deficiencies, micronutrients deficiencies including folic acid, vitamin A and vitamin B12, diseases like malaria, hookworm infestation and schistosomiasis, HIV infection and genetically inherited hemoglobinopathies such as thalassemia. Depending on the severity and duration of anemia and the stage of gestation, there could be different adverse effects including low birth weight and preterm delivery. Treatment of mild anemia prevents more severe forms of anemia, strictly associated with increased risk of fetal-maternal mortality and morbidity.