Effect of iron supplementation from neonatal period on the iron status of6-month-old infants at-risk for early iron deficiency: a randomized interventional trial

The effect of iron supplementation in preterm infants at different gestational ages

BACKGROUND

Iron deficiency (ID) is the most prevalent nutritional deficiency disease in preterm infants, significantly affecting their growth and development. For preterm infants to flourish physically and neurologically, timely iron supplementation is essential. The main goals of this study were to determine whether the present iron supplementation regimen results in iron overload in late preterm infants and whether it can meet the growth requirements of early preterm infants for catch-up.

METHODS

We conducted a prospective follow-up study on preterm infants at the Department of Child Health, West China Second University Hospital, Sichuan University, from January 1, 2020, to August 31, 2020. In this study, 177 preterm infants were divided into two groups based on gestational age-early preterm infants (gestational age < 34 weeks) and late preterm infants (gestational age ≥ 34 weeks and < 37 weeks)-to compare the incidence of iron deficiency, iron status, and physical growth of preterm infants receiving iron supplements (2-4 mg/kg/d).

RESULTS

Iron supplementation considerably reduced the incidence of iron deficiency in preterm infants. The prevalence of iron deficiency in early preterm infants and late preterm infants was 11.3% and 5.1%, respectively, at the corrected gestational age of 3 months; at the corrected gestational age of 6 months, the prevalence was 5.3% and 6.3%, respectively. No preterm infants with iron deficiency were detected in either group at the corrected gestational age of 12 months. Ferritin was substantially lower in early preterm infants (36.87 ± 31.57 ng/ml) than in late preterm infants (65.78 ± 75.76 ng/ml) at the corrected gestational age of 3 months (p < 0.05). A multifactorial regression analysis of factors influencing iron metabolism levels in preterm infants revealed a positive relationship between log10hepcidin, birth weight, and ferritin, with higher birth weights resulting in higher ferritin levels.

CONCLUSIONS

Postnatal iron supplementation at 2-4 mg/kg/d in preterm infants significantly decreases the incidence of ID. There were substantial differences in iron levels across preterm infants of varying gestational ages. A tailored iron supplementation plan based on growth, birth weight, and gestational age may be a more suitable route for iron supplementation. Although the current study found that the postnatal iron status of early preterm infants differed from that of late preterm infants, the actual mechanism of action remains unknown, and large-sample, multicenter clinical studies are required to investigate this further.

Biomarkers of Brain Dysfunction in Perinatal Iron Deficiency

Iron deficiency in the fetal and neonatal period (perinatal iron deficiency) bodes poorly for neurodevelopment. Given its common occurrence and the negative impact on brain development, a screening and treatment strategy that is focused on optimizing brain development in perinatal iron deficiency is necessary. Pediatric societies currently recommend a universal iron supplementation strategy for full-term and preterm infants that does not consider individual variation in body iron status and thus could lead to undertreatment or overtreatment. Moreover, the focus is on hematological normalcy and not optimal brain development. Several serum iron indices and hematological parameters in the perinatal period are associated with a risk of abnormal neurodevelopment, suggesting their potential use as biomarkers for screening and monitoring treatment in infants at risk for perinatal iron deficiency. A biomarker-based screening and treatment strategy that is focused on optimizing brain development will likely improve outcomes in perinatal iron deficiency.

Acknowledging the gap: a systematic review of micronutrient supplementation in infants under six months of age

Background: Micronutrient deficiencies remain common worldwide, but the consequences to growth and development in early infancy (under six months of age) are not fully understood. We present a systematic review of micronutrient interventions in term infants under six months of age, with a specific focus on iron supplementation. Methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and Embase (Ovid) from January 1980 through December 2019. Interventions included iron or multiple micronutrients (MMNs). Results: Of 11,109 records identified, 33 publications from 24 trials were included (19 iron and five MMN supplementation trials). All but one trial (evaluating only morbidity and mortality) evaluated the effect of supplementation on biochemical outcomes, ten reported on growth, 15 on morbidity and/or mortality and six on neuro-behavioural development. Low- and middle- income countries made up 88% (22/25) of the total trial locations. Meta-analysis was not possible due to extensive heterogeneity in both exposure and outcome measures.  However, these trials indicated that infants less than six months of age benefit biochemically from early supplementation with iron, but the effect of additional nutrients or MMNs, along with the impacts on growth, morbidity and/or mortality, and neuro-behavioural outcomes remain unclear. Conclusions: Infants less than six months of age appear to benefit biochemically from micronutrient supplementation. However, well-powered randomised controlled trials are required to determine whether routine supplementation with iron or MMNs containing iron should commence before six months of life in exclusively breast-fed infants in low-resource settings.

Acknowledging the gap: a systematic review of micronutrient supplementation in infants under six months of age

Background: Micronutrient deficiencies remain common worldwide, but the consequences to growth and development in early infancy (under six months of age) are not fully understood. We present a systematic review of micronutrient interventions in term infants under six months of age, with a specific focus on iron supplementation. Methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and Embase (Ovid) from January 1980 through December 2019. Interventions included iron or multiple micronutrients (MMNs). Results: Of 11,109 records identified, 32 publications from 23 trials were included (18 iron and five MMN supplementation trials). All 23 trials evaluated the effect of supplementation on biochemical outcomes, ten reported on growth, 14 on morbidity and/or mortality and six on neuro-behavioural development. Low- and middle- income countries made up 88% (21/24) of the total trial locations. Meta-analysis was not possible due to extensive heterogeneity in both exposure and outcome measures.  However, these trials indicated that infants less than six months of age benefit biochemically from early supplementation with iron, but the effect of additional nutrients or MMNs, along with the impacts on growth, morbidity and/or mortality, and neuro-behavioural outcomes remain unclear. Conclusions: Infants less than six months of age appear to benefit biochemically from micronutrient supplementation. However, well-powered randomised controlled trials are required to determine whether routine supplementation with iron or MMNs containing iron should commence before six months of life in exclusively breast-fed infants in low-resource settings.

Reference range of complete blood count, Ret-He, immature reticulocyte fraction, reticulocyte production index in healthy babies aged 1-4 months

Establishing reference ranges of the complete blood count (CBC), reticulocyte hemoglobin content (Ret-He), immature reticulocyte fraction (IRF), and reticulocyte production index (RPI) helps diagnose a disease related to the changes in erythrocyte indices, white blood count, platelets, and reticulocytes, especially in babies. Therefore, the study aims to establish a reference range for CBC and reticulocyte parameters in healthy babies aged 1-4 months. The study design was a cross-sectional study with descriptive analysis of CBC and reticulocyte in babies aged 1-4 months. Three hundred forty-eight babies met the inclusion criteria. This study recruited 89 babies aged 1 month, 87 babies aged 2 months, 86 babies aged 3 months, and 86 babies aged 4 months. The P5-P95 reference range of healthy babies for hemoglobin (Hb) aged 1 month, 2 months, 3 months, and 4 months was 9.95 to 15.45 g/dL, 9.74 to 13.42 g/dL, 9.51 to 12.40 g/dL, and 10.04 to 13.10 g/dL respectively. The P3-P97 reference range of healthy babies for Hb aged 1 month, 2 months, 3 months, and 4 months was 9.60 to 15.90 g/dL, 9.46 to 13.97 g/dL, 9.26 to 12.82 g/dL, and 10.00 to 13.33 g/dL respectively. This study also defined reference ranges for CBC, Ret-He, IRF, and RPI. The reference range of CBC, Ret-He, IRF, and RPI for healthy babies aged 1-4 months in this study can be used as a benchmark.

Reticulocyte Hemoglobin Equivalent has Comparable Predictive Accuracy as Conventional Serum Iron Indices for Predicting Iron Deficiency and Anemia in a Nonhuman Primate model of Infantile Iron Deficiency

BACKGROUND

Infantile iron deficiency (ID) causes anemia and compromises neurodevelopment. Current screening relies on hemoglobin (Hgb) determination at 1 year of age, which lacks sensitivity and specificity for timely detection of infantile ID. Low reticulocyte Hgb equivalent (RET-He) indicates ID, but its predictive accuracy relative to conventional serum iron indices is unknown.

OBJECTIVES

The objective was to compare diagnostic accuracies of iron indices, red blood cell (RBC) indices, and RET-He for predicting the risk of ID and IDA in a nonhuman primate model of infantile ID.

METHODS

Serum iron, total iron binding capacity, unsaturated iron binding capacity, transferrin saturation (TSAT), Hgb, RET-He, and other RBC indices were determined at 2 wk and 2, 4, and 6 mo in breastfed male and female rhesus infants (N = 54). The diagnostic accuracies of RET-He, iron, and RBC indices for predicting the development of ID (TSAT < 20%) and IDA (Hgb < 10 g/dL + TSAT < 20%) were determined using t tests, area under the receiver operating characteristic curve (AUC) analysis, and multiple regression models.

RESULTS

Twenty-three (42.6%) infants developed ID and 16 (29.6%) progressed to IDA. All 4 iron indices and RET-He, but not Hgb or RBC indices, predicted future risk of ID and IDA (P < 0.001). The predictive accuracy of RET-He (AUC = 0.78, SE = 0.07; P = 0.003) for IDA was comparable to that of the iron indices (AUC = 0.77-0.83, SE = 0.07; P ≤ 0.002). A RET-He threshold of 25.5 pg strongly correlated with TSAT < 20% and correctly predicted IDA in 10 of 16 infants (sensitivity: 62.5%) and falsely predicted possibility of IDA in only 4 of 38 unaffected infants (specificity: 89.5%).

CONCLUSIONS

RET-He is a biomarker of impending ID/IDA in rhesus infants and can be used as a hematological parameter to screen for infantile ID.

Prevalence of Iron Deficiency Anemia and Reference Range of Complete Blood Count, Reticulocyte Parameters in Infants Aged 9-11 Months

BACKGROUND

Iron deficiency anemia (IDA) is still a major global health problem. Determination of reference ranges for complete blood count (CBC), reticulocyte hemoglobin content (Ret-He), immature reticulocyte fraction (IRF), and reticulocyte production index (RPI) are essential to help diagnose a disease.

PURPOSE

The study aims to know the prevalence of IDA, risk factors that influence it, and set a reference range for CBC and reticulocyte parameters in infants aged 9-11 months in Indonesia.

PATIENTS AND METHODS

The study was conducted prospectively at 10 Community Health Centers in Banjarbaru, South Kalimantan, Indonesia, from August 2020 to August 2021.

RESULTS

This study recruited 100 healthy infants (47% boys, 53% girls) aged 9-11 months. The prevalence of IDA was 32%. There is no association between IDA prevalence with the mother's education and occupation, maternal parity, family income, and infant nutritional status (p > 0.05). The reference range for hemoglobin (Hb) at P2.5-P97.5, P3-P97, P5-P95 and mean ± 2SD was 11.06 to 14.34 g/dL, 11.10 to 14.31 g/dL, 11.13 to 13.90 g/dL and 10.57 to 13.65 g/dL, respectively. This study also defined the reference ranges for reticulocyte parameters.

CONCLUSION

The reference range of CBC, Ret-He, IRF, and RPI for healthy infants aged 9-11 months in this study can be used as a benchmark.

Benefits and Risks of Early Life Iron Supplementation

Infants are frequently supplemented with iron to prevent iron deficiency, but iron supplements may have adverse effects on infant health. Although iron supplements can be highly effective at improving iron status and preventing iron deficiency anemia, iron may adversely affect growth and development, and may increase risk for certain infections. Several reviews exist in this area; however, none has fully summarized all reported outcomes of iron supplementation during infancy. In this review, we summarize the risks and benefits of iron supplementation as they have been reported in controlled studies and in relevant animal models. Additionally, we discuss the mechanisms that may underly beneficial and adverse effects.

Effects of iron intake on neurobehavioural outcomes in African children: a systematic review and meta-analysis of randomised controlled trials

Background: Iron deficiency and developmental delay are common in African children. While experimental studies indicate an important role of iron in brain development, effects of iron on child development remain unclear. We aimed to evaluate the effects of iron supplementation or fortification on neurobehavioural outcomes in African children and further summarise these effects in children living in non-African countries for comparison. Methods: We searched PubMed, EMBASE, PsycINFO, Scopus and Cochrane Library for studies published up to 22 nd October 2021. We included randomised controlled trials (RCTs) evaluating effects of iron supplementation or fortification on neurobehavioural outcomes in children. Due to heterogeneity in study methods, we analysed all studies qualitatively and in secondary analyses only seven RCTs with 11 arms were meta-analysed. Results: We identified 2231 studies and included 35 studies (n=9988) in the systematic review. Only five studies (n=1294) included African children while 30 (n=8694) included children living in non-African countries. Of the five African studies, two (n=647) reported beneficial effects of iron supplementation on neurobehavioural outcomes in anaemic children, while three (n=647) found no beneficial effects. Of 30 studies in children living in non-African countries, 10 (n=3105) reported beneficial effects of iron supplementation or fortification on neurobehavioural outcomes, seven (n=786) reported beneficial effects only in children who had iron deficiency, iron deficiency anaemia or anaemia while 13 (n=4803) reported no beneficial effects. Conclusions: There are few studies in African children despite the high burden of iron deficiency and developmental delay in this population. Evidence on the effects of iron supplementation on neurobehavioural outcomes remains unclear and there is need for further well-powered studies evaluating these effects in African populations. PROSPERO registration: CRD42018091278 (20/03/2018).

Effect of Daily Iron Supplementation on Infantile Iron Homeostasis in Preterm Infants

Objective: The aim of this study was to investigate the effects of unified iron supplementation and identify the factors related to the iron homeostasis among preterm infants. Method: A total of 250 preterm infants were divided into neonatal anemic (NA, n = 154) and non-neonatal anemic group (NNA, n = 96). Iron supplements at a dose of 2 mg/kg per day were given from 40 weeks' gestational age to 6 months. Iron status parameters were measured at 3 and 6 months, respectively. Prevalence of iron deficiency (ID) and iron deficiency anemia (IDA), and the correlated factors were analyzed. Growth and side-effects were monitored. Results: There were no significant differences for the prevalence of ID or IDA between the two groups. Multivariate regression analyses showed that higher Hb at birth and early treatment of blood transfusion reduced the risk of ID/IDA at 3 months (all p < 0.05); while higher level of Hb at 3 months (p = 0.004) and formula feeding reduced the occurrence of ID/IDA at 6 months (p < 0.05); males had a 3.35 times higher risk to develop ID/IDA than girls (p = 0.021). No differences in growth and side effects were found. Conclusion: A daily dose of 2 mg/kg iron supplement is beneficial to maintain iron homeostasis in majority preterm infants within 6 months regardless of their neonatal anemia history. Under the routine iron supplementation, Hb level at birth and at 3 months, early treatment of blood transfusion, gender and feeding patterns are the major factors affecting the prevalence of ID/IDA among preterm infants in infancy.

Prevention of iron deficiency anemia in infants and toddlers

Anemia, defined as a low blood hemoglobin concentration, is a major global public health problem. Identification of anemia is crucial to public health interventions. It is estimated globally that 273 million children under 5 years of age were anemic in 2011, and about ~50% of those cases were attributable to iron deficiency (Lancet Global Health 1:e16-e25, 2013). Iron-deficiency anemia (IDA) in infants adversely impacts short-term hematological indices and long-term neuro-cognitive functions of learning and memory that result in both fatigue and low economic productivity. IDA contributes to death and disability and is an important risk factor for maternal and perinatal mortality, including the risks for stillbirths, prematurity, and low birth weight (Comparative Quantification of Health Risks: Global and Regional Burden of Disease Attributable to Selected Major Risk Factors. Ch. 3 (World Health Organization, Geneva, 2004)). Reduction in early infantile anemia and newborn mortality rates is possible with easily implemented, low- to no-cost intervention such as delayed cord clamping (DCC). DCC until 1-3 min after birth facilitates placental transfusion and iron-rich blood flow to the newborn. DCC, an effective anemia prevention strategy, requires cooperation among health providers involved in childbirth, and a participatory culture change in public health. Public intervention strategies must consider multiple factors associated with anemia listed in this review before designing intervention studies that aim to reduce anemia prevalence in infants and toddlers. IMPACT: Anemia, defined as a low blood hemoglobin concentration, is a major global public health problem and identification of anemia is crucial to public health interventions. Delayed cord clamping (DCC) until 1-3 min after birth facilitates placental transfusion and iron-rich blood flow to the newborn. Reduction in early infantile anemia and newborn mortality rates is possible with easily implemented, low- to no-cost intervention such as DCC.