Role of red cell distribution width (RDW) in the detection of iron deficiency anaemia in pregnancy within the first 20 weeks of gestation

Prevalence and Factors Associated with Iron Deficiency Anaemia among Children Aged 6-23 Months in Southwestern Uganda

Iron deficiency anaemia is still a global public health concern with the highest burden among children 6 to 23 months due to their rapid growth spurt exceeding breastmilk supply. Therefore, nutritional supply is a key source of iron to attain the required nutrients for better growth and development. This was a cross-sectional descriptive study done at Ishaka Adventist Hospital (IAH) and Kampala International University Teaching Hospital (KIUTH) from April to July 2022. Participants were consecutively enrolled in the study. Structured questionnaires, 24-hour dietary recall, and clinical assessment were used to obtain data. Data analysis was done using the statistical package for social scientists (SPSS) V22.0. Bivariable and multivariable analyses were done using logistic regression for associations with significance set at P value < 0.05. A total of 364 participants were enrolled, with the majority being males (198, 54.4%) and born at term (333, 91.5%). The modal age was 12-17 months [163(44.8%)] with a mean age of 14.1 months (SD 5.32). The overall prevalence of IDA was 151/364 (41.5%). The factors associated with IDA included male sex (aOR 1.61), current episode of diarrhoea (aOR 1.71), poor meal frequency (aOR 1.78), no vegetable consumption (aOR 2.47), and consuming fruits once (aOR 1.97) in 7 days preceding the study. The study finds a high prevalence of IDA among infants 6-23 months with at least four in 10 being affected. Screening for IDA should be recommended in male children with current diarrhoea, poor intake of fruits and vegetables, and poor meal frequency. The Mentzer index is an equally good alternative screening test for IDA.

Magnitude and morphological types of anemia differ by age among under five children: A facility-based study

Background

World Health Organization recently acknowledged the proportion of anemia attributable to iron deficiency among under-five children could be lower than the previously assumed 50%. Ethiopia reported 8.6% and 12.3% prevalence of iron deficiency anemia by serum ferritin and soluble transferrin receptor respectively. However, evidence generated from large samples on the magnitude of different types of anemias is limited. We aimed to determine the prevalence and morphological types of anemia in relation to age.

Methods

A retrospective analysis was conducted using electronic records of hemoglobin and red blood cell indices of 4739 children of 6–59 months of age who visited Hawassa University Comprehensive and Specialized Hospital from May 2017 to May 2019. Microcytic hypochromic morphology combined with high red cell distribution width was used to estimate the prevalence of iron deficiency.

Results

About 44.7% of the children were anemic. Anemia affected 6–23 months old children (53.1%) more than 24–59 (37.2%) months (p < 0.001) with no difference among boys and girls. Iron deficiency and iron-deficiency anemia, as explained by microcytic hypochromic morphology with high red cell distribution width combined model, were estimated to be 38.6% and 24.1%, respectively. About 54% of anemic children had iron deficiency which was higher among 6–23 months (63.5%) than 24–59 months (41.8%) (P < 0.001; X² = 98.883). Regardless of anemia status, iron deficiency was two-fold higher among 6–23 months old children than 24–59 months of age. On the contrary, normocytic normochromic anemia affected significantly 24–59 months old children (23.1%) compared to 6–23 months. Less than 6% of the total anemia was macrocytic showing no significant relation with age. About 96% of macrocytic anemia was coupled with high red cell distribution width, indicating folate and vitamin B₁₂ deficiency.

Conclusions

Microcytic hypochromic anemia with high red cell distribution width was the most prevalent type affecting primarily under two children. Normocytic normochromic anemia was significant among 24–59 months while macrocytic anemia had no age-related pattern. An in-depth study of causes of anemia other than iron deficiency particularly among 24–59 months children is essential.

Red blood cell distribution width-standard deviation but not red blood cell distribution width-coefficient of variation as a potential index for the diagnosis of iron-deficiency anemia in mid-pregnancy women

The aim of this study was to compare the diagnostic values of red blood cell distribution width-coefficient of variation (RDW-CV) and red blood cell distribution width-standard deviation (RDW-SD) in mid-pregnancy women with iron deficiency anemia (IDA). To obtain the results, 115 mid-pregnancy women with IDA, defined as the IDA group, and 142 healthy mid-pregnancy women, selected as the control group, were enrolled in this study. Hematological parameters and ferritin concentrations in the serum were analyzed. The efficiency of RDW-CV and RDW-SD to distinguish IDA from mid-pregnancy women was evaluated using receiver operating characteristic (ROC) curves. The RDW-SD value in the IDA group was significantly higher than that in the control group (p < 0.05), while the RDW-CV value did not differ between them (p = 0.84). Significantly negative correlations were found between RDW-CV (r = −0.297, p = 0.001), RDW-SD (r = −0.404, p = 0.000), and serum ferritin in the IDA group but not in the control group. For the diagnosis of IDA, RDW-CV and RDW-SD produced areas under the ROC curves of 0.58 and 0.84. To conclude, our results suggest that RDW-SD, but not RDW-CV, can be used as a diagnostic index of IDA for mid-pregnancy women.

Magnitude of Anemia and Its Associated Factors among Pregnant Women Attending Antenatal Care at Najo General Hospital, Northwest Ethiopia

Anemia is one of the major causes of morbidity for pregnant women in resource-limited regions. Yet robust research-based evidence on this vital public health problem in remote areas where the problem could be massive is quite limited in Ethiopia, one of the developing countries. Thus, this study is aimed to assess the magnitude of anemia and its associated risk factors among pregnant women attending one of the health facilities in Ethiopia. A facility-based cross-sectional study design was employed in 2019. A total of 384 pregnant women attending the antenatal care (ANC) unit of Najo General Hospital, Northwest Ethiopia, were included in the study. Their sociodemographic characteristics, and medical, obstetric, and gynecological history were collected using pretested interview questionnaires. Blood samples were collected from each participant for the determination of malaria parasite and hemoglobin (Hb) level. In addition, stool samples were collected for examination of intestinal parasites. Data were analyzed using Statistical Package for Social Science (SPSS) software version 25. The overall magnitude of anemia among pregnant women was 37.8% (95% CI, 32.8%–42.3%). The proportion of mild anemia, moderate anemia, and severe anemia was 24%, 11%, and 2.3%, respectively. Some variables such as absence of malaria infection (AOR: 0.195, 95% CI: 0.066–0.576), lack of history of abortion (AOR: 0.469, 95% CI: 0.265–0.830), and absence of history of anemia (AOR: 0.227, 95% CI: 0.134–0.385) were identified as protective variables of anemia during pregnancy, while urban residence (AOR: 1.753, 95% CI: 1.013–3.034) was unexpectedly found as a predisposing factor. Despite the higher number of anemic pregnant women observed in the current study, pregnancy-associated anemia is moderate public health importance in the study area.

Classic and emergent indicators for the assessment of human iron status

Iron deficiency is the leading cause of anemia, a significant global public health problem. Different methods exist for assessing iron nutritional status, including laboratory tests that focus on storage, transportation, and iron functional compartment parameters. Classical markers such as bone marrow, serum iron, ferritin, hemoglobin, erythrocyte parameters, transferrin, transferrin receptors, and zinc protoporphyrin are discussed in this review. Additional parameters calculated from these indicators, including transferrin saturation, ferritin index and Thomas plot, and some emergent parameters such as hepcidin, erythroferrone, and low hemoglobin density are also discussed. There is no a single indicator for assessing iron nutritional status. Therefore, the use of more than one indicator may be the best practice to obtain the correct diagnosis, also considering the influence of inflammation/infection on many of these indicators. The constant validation of the current parameters, the improvement of assessment methods, and the identification of new indicators will be the key to refine the assessment of iron nutritional status and the right choice of treatment for its improvement.

Utility of erythrocyte indices in identifying iron depletion in pregnancy

Background

Iron deficiency anaemia in pregnancy is common and is a major cause of maternal and neonatal morbidity worldwide. Serum ferritin is the current gold standard test for identifying iron depletion, with a cut-off value of 30 µg/L. Recent studies in low- and middle-income countries have identified mean cell haemoglobin concentration as a surrogate marker for the prediction of iron depletion.

Methods

We studied values from 786 antenatal blood results from 2018 in Oxford, UK, and correlated the red cell indices with serum ferritin measurements.

Results

Haemoglobin, mean cell volume, mean cell haemoglobin and mean cell haemoglobin concentration have low specificity and sensitivity for the identification of iron depletion.

Conclusions

We found that haemoglobin, mean cell volume, mean cell haemoglobin and mean cell haemoglobin concentration do not have sufficient predictive value in this population to be used as a screening test for non-anaemic iron depletion.

Study on the Effect of Severity of Maternal Iron Deficiency Anemia on Regulators of Angiogenesis in Placenta

Aims: In this study, we hypothesized that maternal anemia leads to altered expression of angiogenic proteins vascular endothelial growth factor (VEGF), placental growth factor (PLGF), nitrotyrosine (NT) residues, and endothelial nitric oxide synthase (e-NOS) in the placenta. Hence, we study the expression of the abovementioned proteins in the placentas of mothers with different grades of anemia. Materials and methods: Our study was conducted in 48 pregnant women (36-40 weeks of gestation), who were divided into four groups-normal, mild, moderate, and severe anemia. After delivery, the expression of the angiogenic proteins was studied in their placentas by immunohistochemistry. Results: In our study, 58.3% of the pregnant women were anemic, among which 20.83% had mild anemia, 18.75% had moderate anemia, and 18.75% had severe anemia. Immunohistochemical staining intensity for VEGF, PLGF, NT residues, and e-NOS proteins was observed to be higher in the placentas of anemic women when compared with the non-anemic women. Conclusion: Our study showed that there is an increased expression of angiogenic proteins in the placentas of anemic mothers, which probably is an adaptive response leading to changes in placental vessels.

Red blood cell distribution width in pregnancy: a systematic review

Anisocytosis has been associated with the severity and prognosis of several acute and chronic diseases, as well as physiological conditions such as pregnancy. Anisocytosis is quantified by the red blood cell distribution width (RDW), expressed as the ratio, multiplied by 100, between the standard deviation (SD) of red blood cell volumes and the mean corpuscular volume, or as the SD of erythrocyte volumes (RDW-SD). The aim of the present review was to report the state of the art on the physiological values and the putative diagnostic and prognostic roles of RDW in complicated pregnancy. Literature research for articles published in the last ten years was conducted in Pubmed, Web of Science, ClinicalTrials.gov, and Scopus databases. Abstracts were independently screened by two investigators. If relevant, full articles were retrieved. References, in these articles, citing relevant reviews or original studies were also accessed to identify additional eligible studies. Any disagreement between the reviewers was resolved by a third investigator. A total of 28 studies were included in the review. These studies reported changes in RDW values during physiological pregnancy, and associations between the RDW and several pregnancy complications including anaemia, preeclampsia, gestational diabetes, and recurrent miscarriage. This review provides background information for establishing physiological and pathological RDW values in pregnancy for diagnostic and prognostic use in clinical practice.

Could the erythrocyte indices or serum ferritin predict the therapeutic response to a trial with oral iron during pregnancy? Results from the Accuracy study for Maternal Anaemia diagnosis (AMA)

Background

Treatment of maternal iron-deficiency anaemia can reduce risks of prematurity and low birth weight; hence a reliable diagnosis of maternal iron needs is critical. However, erythrocyte indices and serum ferritin have shown a weak correlation with iron status during pregnancy. This study verified the accuracy of those tests to predict the responsiveness to a therapeutic test with oral iron as reference standard for iron deficiency in pregnant women.

Methods

A prospective diagnostic study phase 3 was conducted in a single prenatal care center in Northeast Brazil. Between August 2011 and October 2012 a consecutive sampling included 187 women in their 2^nd-3^rd trimesters of low-risk pregnancy and having anaemia (haemoglobin <11.0 g/dL). Until December 2012, 139 women completed a trial with daily pills of ferrous sulfate (40 mg of iron), during 23 to 125 days. Haemoglobin (Hb), other erythrocyte indices and ferritin (index-tests) were assessed pre-treatment by automated analyzers. Hb was performed also post-treatment to assess the therapeutic response by its post-pretreatment differences. We estimated sensitivity (Se), specificity (Sp), predictive values (PV), likelihood ratios (LR), diagnostic Odds Ratio (OR), area under Receiver Operating Characteristic curve (AUC), accuracy ratio and agreement coefficient of the index-tests against an increase of at least 0.55 Hb Z-score (reference standard test). We calculated the Z-scores according to the reference population from Centers for Disease Control and Prevention.

Results

Hb had a mean increase of 0.24 Z-score after 30 iron pills (p 0.013). All index-tests demonstrated PV- above 70 %, PV+ around 40 %, LR around 1.0, and AUC of 0.5 to 0.6. Hb and haematocrit had Se of 50 % (95 % CI 40 to 70); and Sp of 59 % (95 % CI 43 to 74) and 47 % (95 % CI 38 to 57), respectively. Ferritin, Mean Corpuscular Volume, Mean Corpuscular Haemoglobin, Mean Corpuscular Haemoglobin Concentration and Red blood cell Distribution Width had Se below 40 % with Sp above 70 %.

Conclusions

Erythrocyte indices and ferritin could not predict the iron needs of anemic pregnant women. Increases of Hb Z-scores after a short treatment with oral iron may be a reliable therapeutic test.

Trial registration

World Health Organization International Clinical Trials Registry Platform U1111-1123-2605; Brazilian Registry of Clinical Trials RBR-237wbg, registered 28 July 2011

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-1005-x) contains supplementary material, which is available to authorized users.

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.

Red blood cell distribution width is not correlated with preeclampsia among pregnant Sudanese women

BACKGROUND

Preeclampsia is a leading cause of maternal and perinatal mortality worldwide. The exact etiology of preeclampsia is unknown, but the inflammatory process is postulated as one of the etiologies. Red blood cell distribution width (RDW) is a measure of anisocytosis (variation of red cell size) and is associated with hypertension and diabetic ketoacidosis. There are few data on the association between RDW and preeclampsia. This study aimed to investigate the association between RDW and preeclampsia.

METHODS

A case-control study was conducted at Khartoum Hospital, Sudan, during June to August 2012. Cases were women with preeclampsia and healthy women were controls. Sociodemographic characteristics, obstetrics, and clinical data were recorded. The complete blood count, including RDW, was measured using an automated hematology analyzer.

RESULTS

The cases and controls (65 women in each arm) were matched in their basic characteristics. There was no difference in the mean (SD) RDW between women with preeclampsia and controls (14.5 ± 1.8% vs. 14.4 ± 1.4%, P = 0.710). There was also no difference in the mean RDW between women with mild and severe preeclampsia (14.7 ± 1.9% vs. 13.9 ± 1.4%, P = 0.144. In logistic regression, there was no association between RDW and preeclampsia (OR = 0.9, CI = 0.7-1.1, P = 0.952).

CONCLUSIONS

RDW levels are not associated with the presence or severity of preeclampsia.

VIRTUAL SLIDES

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Red blood cell distribution width and iron deficiency anemia among pregnant Sudanese women

BACKGROUND

Iron deficiency anemia (IDA) is a major health problem during pregnancy and it has adverse effects on the mother and the newborn. Red cell distribution width (RDW), which is a quantitative measure for red cell size variation (anisocytosis), is a predictor of IDA. Little is known regarding RDW and IDA during pregnancy.

METHODS

A cross sectional study was conducted at the antenatal clinic of Khartoum Hospital, Sudan, to determine the performance of RDW in the diagnosis of IDA using serum ferritin as a gold standard.

RESULTS

Among 194 pregnant women with a gestational period of 21.4 ± 6.5 weeks, 57 (29.4%) had IDA according to serum ferritin levels (<15 μg/l) and 61 (31.4%) had IDA according to RDW (>14.5). The sensitivity, specificity, positive predictive value, and negative predictive value of RDW where serum ferritin was the gold standard were 43.8% (95% CI: 31.4-57.0%), 73.7% (95% CI: 65.8-80.5%), 41.0% (95% CI: 29.2-53.6%), and 76.0% (95% CI: 68.1-82.6%), respectively.

CONCLUSIONS

In this study, we found that RDW has a poor performance in diagnosing IDA among pregnant women compared with serum ferritin as the gold standard.