Randomized trial of iron supplementation versus routine iron intake in VLBW infants

The Effects of Iron Administration on Anemia Development during the 7th and 21st Day of Life in Premature Newborns: A Prospective Cohort Study

Background and Objectives: The administration of iron to premature newborns is a common intervention aimed at preventing iron deficiency (ID). However, there is no consensus on the optimal timing and dosage for iron supplementation in this population. This study evaluates the effects and potential adverse outcomes of administering iron on the 7th and 21st days of life in premature infants. Materials and Methods: This research was conducted on 108 premature neonates at the "Louis Turcanu" Children's Emergency Clinical Hospital in Timisoara, Romania. The study population was divided into a control group of 48 newborns who did not receive iron supplementation and an intervention group of 60 newborns who did. The analysis utilized univariate and multivariate regression to examine binary outcomes. Results: The findings indicate that iron supplementation significantly increased the risk of anemia during the premature period at 21 days of life, as demonstrated by both univariate and multivariate regression analyses, with an odds ratio (OR) of 2.40 (95% CI, 1.01-5.68) and an adjusted odds ratio (AOR) of 2.75 (95% CI, 1.06-7.11), respectively. Contrary to expectations, iron supplementation did not significantly alter the risk of abnormal serum ferritin or iron levels at 21 days of life, according to the univariate analysis (p = 0.380 and p = 0.526, respectively). Conclusions: The observed increase in the risk of anemia without a corresponding improvement in the serum ferritin or iron levels suggests the need for further investigation into alternative strategies for iron supplementation in premature newborns.

Accuracy of reticulocyte hemoglobin for diagnosing iron deficiency in former very preterm infants: a population-based cohort study

Background

Serum ferritin (SF) is commonly used to diagnose iron deficiency (ID) but has limitations. Reticulocyte hemoglobin (Ret-He) is being increasingly used for ID diagnosis. This study aimed to assess accuracy of Ret-He for ID diagnosis in former very preterm infants (VPI) at 4-6 months corrected age (CA).

Methods

A retrospective population-based cohort study was conducted on all live VPI born between 23 and 30 weeks of gestational age (GA) in Nova Scotia from 2012 to 2018. Infants underwent SF and Ret-He testing at 4-6 months CA. ID was defined using two definitions. The first defined ID as SF < 20 mcg/L at both 4- and 6-months CA, and the second as SF < 30 mcg at at both 4- and 6-months CA. The accuracy of Ret-He for identifying ID was assessed using the area under the receiver operating characteristic curve (AUC).

Results

ID was present in 39.7% (62) of 156 infants in the first definition and 59.6% (93) in the second at 4-6 months CA. The AUC of Ret-He for ID diagnosis was 0.64 (p = 0.002) in the first definition and 0.59 (p = 0.04) in the second. The optimal cut-off was 29.4pg in the first and 29.7 in the second definition. The sensitivity, specificity, positive predictive value (PPV), and negative predictive values (NPV) at the 29.4 pg cut-off were 50.0%, 78.7%, 60.8%, and 70.5% for definition 1 and 44.1%, 74.6%, 71.9%, and 47.5% at the 29.7pg cut-off for definition 2.

Conclusion

Ret-He had low diagnostic accuracy for ID diagnosis in former VPI. Caution is advised when using Ret-He alone for ID diagnosis. Further research is needed to establish optimal approaches for identifying ID in VPI.

Enteral Iron Supplementation in Preterm or Low Birth Weight Infants: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Iron is needed for growth and development of infants globally, but preterm and low birth weight (LBW) infants are at risk for severe iron deficiencies. To assess the effect of enteral iron supplementation on mortality, morbidity, growth, and neurodevelopment outcomes in preterm or LBW infants fed human milk. Secondary objectives were to assess the effect on biomarkers and dose and timing.

METHODS

Data sources include PubMed, Embase and Cochrane Library databases to March 16, 2021. Study Selection includes controlled or quasi experimental study designs. Two reviewers independently extracted data.

RESULTS

Eight trials (eleven reports; 1093 participants, 7 countries) were included. No trials reported mortality. At latest follow-up, there was little effect on infection (very low certainty evidence, 4 studies, 401 participants, relative risk [RR] 0.98, 95% confidence interval [95% CI] 0.56 to 1.73, I2 = 0.00%) and necrotising enterocolitis (3 studies, 375 participants, RR 1.47, 95% CI 0.68 to 3.20, I2 = 0.00%). There was an increase in linear growth (length) (moderate certainty evidence, 3 studies, 384 participants, mean difference 0.69 cm, 95% CI 0.01 to 1.37, I2 = 0%) but little effect on weight, head circumference, or cognitive development. There was an improvement in anemia (moderate certainty evidence, 2 studies, 381 participants, RR 0.25, 95% CI 0.10 to 0.62, I2 = 0.00%) but no effect on serum ferritin. Limitations include heterogeneity in the included studies.

CONCLUSIONS

There are important benefits for human milk-fed preterm and LBW infants from enteral iron supplementation. However, more randomized control trials are required to improve the certainty of evidence.

Iron Supplementation Is Associated with Improvement of Motor Development, Hemoglobin Level, and Weight in Preterm Infants during the First Year of Life in China

Iron supplementation is recommended for preterm infants due to impaired iron endowment. However, the health outcomes of this recommendation remain controversial. Thus, this study aimed to determine the association of iron supplementation with neurobehavioral development, hemoglobin (Hb), and anthropometric characteristics in preterm infants. A retrospective cohort design was applied to collect data from 1568 preterm infants at 0–3 months of corrected age (mo CA) from a hospital in South China. Infants were categorized into a 3-month iron supplementation group (IG, n = 697) or a control group (CG, n = 871) according to medical records, and then followed through to 12 mo CA. Data on neurobehavioral development, anthropometry, Hb level, history of diseases, and nutrition were collected at 3, 6, and 12 mo CA. The results showed that, compared with the CG, iron supplementation was positively related to improved gross motor skills and weight at 6 mo CA (β = 1.894, β = 5.322) and 12 mo CA (β = 4.019, β = 6.830) and fine motor skills at 12 mo CA (β = 1.980), after adjustment for confounding factors including illness, nutritional supplements, and diet. Iron supplementation was also related to elevated Hb levels and its increase at 3 mo CA (β = 2.196, β = 3.920) and 6 mo CA (β = 3.011, β = 7.259). In conclusion, iron supplementation for 3 months in Chinese preterm infants is positively associated with improved motor development, elevated Hb levels, and higher body weight during the first year of life.

Nutritional Supplements to Improve Outcomes in Preterm Neonates

Preterm infants are at higher risk of mortality and morbidity compared with those born at term. Nutrition-related morbidities include poor growth, immune deficiency, nutritional deficiencies, and adverse long-term neurodevelopment. In addition to macronutrients, many nutritional supplements have been used to enhance growth and development, and decrease infections. Nutrients can enhance preterm infants' immune status, optimize the microbiome, improve growth and development, and influence the risk of necrotizing enterocolitis, sepsis, and other outcomes.

Thresholds for blood transfusion in extremely preterm infants: A review of the latest evidence from two large clinical trials

There are two recently completed large randomized clinical trials of blood transfusions in the preterm infants most at risk of requiring them. Liberal and restrictive strategies were compared with composite primary outcome measures of death and neurodevelopmental impairment. Infants managed under restrictive guidelines fared no worse in regard to mortality and neurodevelopment in early life. The studies had remarkably similar demographics and used similar transfusion guidelines. In both, there were fewer transfusions in the restrictive arm. Nevertheless, there were large differences between the studies in regard to transfusion exposure with almost 3 times the number of transfusions per participant in the transfusion of prematures (TOP) study. Associated with this, there were differences between the studies in various outcomes. For example, the combined primary outcome of death or neurodevelopmental impairment was more likely to occur in the TOP study and the mortality rate itself was considerably higher. Whilst the reasons for these differences are likely multifactorial, it does raise the question as to whether they could be related to the transfusions themselves? Clearly, every effort should be made to reduce exposure to transfusions and this was more successful in the Effects of Transfusion Thresholds on Neurocognitive Outcomes (ETTNO) study. In this review, we look at factors which may explain these transfusion differences and the differences in outcomes, in particular neurodevelopment at age 2 years. In choosing which guidelines to follow, centers using liberal guidelines should be encouraged to adopt more restrictive ones. However, should centers with more restrictive guidelines change to ones similar to those in the studies? The evidence for this is less compelling, particularly given the wide range of transfusion exposure between studies. Individual centers already using restrictive guidelines should assess the validity of the findings in light of their own transfusion experience. In addition, it should be remembered that the study guidelines were pragmatic and acceptable to a large number of centers. The major focus in these guidelines was on hemoglobin levels which do not necessarily reflect tissue oxygenation. Other factors such as the level of erythropoiesis should also be taken into account before deciding whether to transfuse.

Staff awareness and bundling reduce skin breaks and blood tests in neonatal intensive care

AIM

Skin breaks (SBs) for procedures and blood sampling are common in neonatal intensive care units (NICU), contributing to pain, infection risk and anaemia. We aimed to document their prevalence, identify areas for improvement and, through staff awareness, reduce their frequency.

METHODS

Quality improvement project via prospective audit at a tertiary-level NICU in Australia was conducted. All infants admitted to the NICU for >24 h during two audit periods were included in the study. A specifically designed bedside audit tool was used to prospectively document all SB and blood tests performed on infants during a 4-week audit period (audit 1). Results were reviewed to identify areas for improvement, and disseminated to staff at unit meetings, shift handover and email. Following education and awareness, the audit was repeated (audit 2), and data were compared. Frequency of SB and blood tests performed was measured. Data were tested for normality and analysed using parametric or non-parametric tests where appropriate.

RESULTS

There were 52 NICU admissions during each audit period (104 total), with 34 (65%) and 31 (60%) having audit sheets completed, respectively. Median (interquartile range) gestational age and mean (standard deviation) birthweight were 29 (26.3-35) weeks and 1836 (1185) g for audit 1, 30 (28.5-31.5) weeks and 1523 (913) g for audit 2. The reduction in total blood tests (mean) was 36.3%, skin breaks per admitted baby day reduced by 60% and total blood volume sampled (mean) by 37.7%.

CONCLUSIONS

A quality improvement project by prospective audit and staff education was associated with reductions in frequency of skin breaks and blood tests in the NICU.

Eligibility Criteria and Representativeness of Randomized Clinical Trials That Include Infants Born Extremely Premature: A Systematic Review

OBJECTIVE

To assess the eligibility criteria and trial characteristics among contemporary (2010-2019) randomized clinical trials (RCTs) that included infants born extremely preterm (<28 weeks of gestation) and to evaluate whether eligibility criteria result in underrepresentation of high-risk subgroups (eg, infants born at <24 weeks of gestation).

STUDY DESIGN

PubMed and Scopus were searched January 1, 2010, to December 31, 2019, with no language restrictions. RCTs with mean or median gestational ages at birth of <28 weeks of gestation were included. The study followed the PRISMA guidelines; outcomes were registered prospectively. Data extraction was performed independently by multiple observers. Study quality was evaluated using a modified Jadad scale.

RESULTS

Among RCTs (n = 201), 32 552 infants were included. Study participant characteristics, interventions, and outcomes were highly variable. A total of 1603 eligibility criteria were identified; rationales were provided for 18.8% (n = 301) of criteria. Fifty-five RCTs (27.4%) included infants <24 weeks of gestation; 454 (1.4%) infants were identified as <24 weeks of gestation.

CONCLUSIONS

The present study identifies sources of variability across RCTs that included infants born extremely preterm and reinforces the critical need for consistent and transparent policies governing eligibility criteria.

Intestinal Microbiome in Preterm Infants Influenced by Enteral Iron Dosing

OBJECTIVES

The aim of the study was to compare the intestinal microbiome in very low birth weight (VLBW) infants who received different enteral iron supplementation (EIS) doses.

STUDY DESIGN

Longitudinal stool collection in 80 VLBW infants were conducted up to 2 months postnatally in a prospective study. The 16S rRNA regions V4 was used to calculate microbiome compositions and the Piphillin software was used for bacterial functional prediction. Linear mixed effect models and Wilcoxon rank-sum tests were performed to examine the relationships between initial EIS dosage and stool microbiome and bacterial functional potential.

RESULTS

There were 105 samples collected before and 237 collected after EIS started from infants with birth gestational age and weight of 28.1 ± 2.4 weeks and 1103 ± 210 g, respectively. The average postnatal age at start of EIS was 17.9 ± 6.9 days and the average initial EIS dose was 4.8 ± 1.1 mg · kg-1 · day-1. Infants who were started on ≥6 mg · kg-1 · day-1 had higher abundances of Proteus and Bifidobacterium and a lower alpha diversity than those started on lower doses (P < 0.05). Infants given higher EIS doses had higher bacterial predicted functional potentials for ferroptosis and epithelial invasion after 2 weeks post EIS.

CONCLUSIONS

Higher EIS dosage is linked to higher abundances of Proteus and Bifidobacterium, and a less diverse microbiome and higher predicted potential of bacterial epithelial invasion. These observational findings should be further studied in a randomized study to elucidate the optimal dosage of EIS in VLBW infants.

Iron supplementation in preterm and low-birth-weight infants: a systematic review of intervention studies

Context

Enteral iron supplementation in preterm infants is recommended to supply sufficient iron for growth and development without increasing the risk of iron overload. However, the current recommendations date from 2010 and are based on limited evidence.

Objective

This systematic review aimed to investigate the effects of enteral iron supplementation on iron status, growth, neurological development, and adverse clinical outcomes in preterm (<37 weeks’ gestation) and low-birth-weight (LBW, <2500 g) infants.

Data sources

The PubMed/Medline and Cochrane Library databases were searched to 31 October 2018.

Data extraction

Of the 684 records identified, 27 articles, describing 18 randomized controlled trials (RCTs) plus 4 nonrandomized interventions, were included. Using the Cochrane Collaboration’s criteria, study quality was found to be poor to fair overall.

Results

Most articles (23/27) reported iron status indices; supplementation for ≥8 weeks resulted in increased hemoglobin and ferritin concentrations and a reduction in iron deficiency and anemia. No article reported on iron overload. Growth-related parameters reported in 12 articles were not affected by supplementation. Among the 7 articles on neurological development, a positive effect on behavior at 3.5 and 7 years was observed in one Swedish RCT. No association was found between supplementation and adverse clinical outcomes in the 9 articles reporting on studies in which such data was collected.

Conclusions

Long-term iron supplementation appears to result in improved iron status and a reduction in iron deficiency and anemia in preterm and LBW infants. However, high-quality evidence regarding the long-term effects of supplementation on functional health outcomes is lacking. Iron overload has largely been ignored. Well-designed, long-term, dose-response RCTs are required to ascertain the optimal dose and delivery method for the provision of dietary iron in preterm infants, with consideration of short- and long-term health effects.

Systematic Review Registration

PROSPERO registration no. CRD42018085214.

Enteral iron supplementation, red blood cell transfusion, and risk of bronchopulmonary dysplasia in very-low-birth-weight infants

BACKGROUND

Enteral iron supplementation and RBC transfusions are routinely administered to very-low-birth-weight (VLBW) infants, although the potential risks of these exposures have not been adequately quantified. This study evaluated the association between the cumulative dose of enteral iron supplementation, total volume of RBCs transfused, and risk of bronchopulmonary dysplasia (BPD) in VLBW infants.

STUDY DESIGN AND METHODS

Retrospective, multicenter observational cohort study in Atlanta, Georgia. Cumulative supplemental enteral iron exposure and total volume of RBCs transfused were measured until the age at assessment of BPD. Multivariable generalized linear models were used to control for confounding, and the reliability of the factors was assessed in 1000 bootstrap models.

RESULTS

A total of 598 VLBW infants were studied. In multivariable analyses, a greater cumulative dose of supplemental enteral iron exposure was associated with an increased risk of BPD (adjusted relative risk per 50-mg increase, 1.07; 95% confidence interval [CI], 1.02-1.11; p = 0.002). Similarly, a greater volume of RBCs transfused was associated with a higher risk of BPD (adjusted relative risk per 20-mL increase, 1.05; 95% CI, 1.02-1.07; p < 0.001). Both factors were reliably associated with BPD (>50%). Volume of RBCs transfused was similar to gestational age in reliability as a risk factor for BPD (present in 100% of models) and was more reliable than mechanical ventilation at 1 week of age.

CONCLUSION

The cumulative dose of supplemental enteral iron exposure and total volume of RBC transfusion are both independently associated with an increased risk of BPD in VLBW infants.

Necrotizing enterocolitis and high intestinal iron uptake due to genetic variants

BackgroundIntestinal iron is a nutritional compound, which is essential for enteric microbiota. We evaluated the hypothesis that polymorphisms, which are known modifiers of intestinal iron uptake in adults, are associated with necrotizing enterocolitis (NEC) in preterm infants.MethodsPreterm infants (birth weight below 1,500 g) were studied. Single-nucleotide polymorphisms with known effects on serum iron levels (rs1800562, rs1799945, and rs855791) were determined using PCR. The effects of polymorphisms on NEC surgery were tested by Mendelian randomization. Outcome data were compared with χ²-test, Fisher's exact test, t-test, and Cochran-Armitage test for trend and multiple logistic regression analysis.ResultsComplete genotyping data were available for 11,166 infants. High serum iron levels due to rs855791 genotype were associated with a significantly reduced risk of NEC surgery (odds ratio (OR) 0.265; 95% confidence interval (CI) 0.11-0.65; adjusted P=0.011). Carriers of the rs855791 A-allele not receiving prophylactic probiotics had a higher risk of NEC surgery (OR 1.12, 95% CI 1.08-1.70, nominal P=0.002). Prophylactic treatment with probiotics was associated with a reduced risk of NEC surgery in carriers of the rs855791 A-Allele. No differences were found with regard to other short- or long-term outcome data.ConclusionPolymorphisms inducing lower intestinal iron uptake like the rs855791 A-allele might be an underestimated risk factor for NEC.

Anemia and transfusion in the neonate

Neonatal anemia is a frequent occurrence in neonatal intensive care units. Red blood cell transfusion criteria in case of blood loss are clearly defined but optimal hemoglobin or hematocrit thresholds of transfusion for anemia due to decreased production or increased destruction are less evident. This review focuses on the causes of anemia in the newborn period and the most recent evidence-based treatment options, including transfusion and erythropoiesis-stimulating agents.

Minimizing blood loss and the need for transfusions in very premature infants

Reducing blood loss and the need for blood transfusions in extremely preterm infants is part of effective care. Delayed cord clamping is well supported by the evidence and is recommended for infants who do not immediately require resuscitation. Cord milking may be an alternative to delayed cord clamping; however, more research is needed to support its use. In view of concerns regarding the increased risk for cognitive delay, clinicians should avoid using hemoglobin transfusion thresholds lower than those tested in clinical trials. Higher transfusion volumes (15 mL/kg to 20 mL/kg) may decrease exposure to multiple donors. Erythropoietin is not recommended for routine use due to concerns about retinopathy of prematurity. Elemental iron supplementation (2 mg/kg/day to 3 mg/kg/day once full oral feeds are achieved) is recommended to prevent later iron deficiency anemia. Noninvasive monitoring (eg, for carbon dioxide, bilirubin) and point-of-care testing reduce the need for blood sampling. Clinicians should strive to order the minimal amount of blood sampling required for safe patient care, and cluster samplings to avoid unnecessary skin breaks.

Reticulocyte haemoglobin content as a marker of iron deficiency

OBJECTIVE

To evaluate reticulocyte haemoglobin content (CHr), compared with ferritin, transferrin saturation (TS) and mean corpuscular volume (MCV), as a marker of iron deficiency (ID).

DESIGN

Retrospective analysis of clinically indicated blood samples taken between February 2010 and October 2012.

SETTING

Single-centre neonatal care unit.

PATIENTS

210 very preterm (gestational age <32 weeks) or very low birthweight infants (birth weight <1500 g) at 3-4 months corrected age.

MAIN OUTCOME MEASURES

Complete blood count, CHr, ferritin and TS determined as part of a standard follow-up examination. To detect the optimal CHr cut-off, ID was defined by the presence of more than two of the following three criteria: MCV <75 fL, TS <10%, ferritin <30 µg/L.

RESULTS

210 preterm infants were included at a corrected age of (median (IQR)) 3.5 (3.0-4.0) months and with a CHr of 29.7 (28.6-30.7) pg. There were correlations between CHr and MCV (r=0.54, p <0.0001) and between CHr and TS (r=0.44, p <0.0001). There were 27 (13.4%) iron-deficient infants, and two infants (1%) fulfilled criteria of ID-anaemia. CHr was lower in infants with ID (26.4 (23.8-28.7) pg) than in those without (29.9 (29.0-30.8) pg, p <0.0001). The optimal CHr cut-off for detecting ID was 29 pg (sensitivity 85%, specificity 73%). Areas under the receiver operating characteristic curve for detection of ID tended to be higher for CHr compared with ferritin (0.92 vs 0.75), TS (0.90 vs 0.82) and MCV (0.81 vs 0.72).

CONCLUSIONS

CHr seems to be a suitable marker for latent ID in preterm infants at 3-4 months corrected age and may be superior to ferritin, TS and MCV.

Meeting iron needs for infants and children

PURPOSE OF REVIEW

Iron deficiency early in life is associated with impaired neurological development. This study reviews the latest research on how to best meet iron requirements in infants and children.

RECENT FINDINGS

There is concurrent evidence that delayed cord clamping is well tolerated and improves infant iron stores. Iron supplements or enriched complementary foods starting before 6 months of life do not reduce iron deficiency prevalence in low-risk populations. However, for low birth weight infants, iron supplements before 6 months of life have long-term benefits. Iron deficiency anaemia (IDA) during the second half year of life is rare in countries with high compliance to iron-rich complementary foods, but remains a major problem globally. In high-risk populations, iron supplementation reduces IDA and possibly improves growth. However, increased risk of infections is a concern and optimal preventive strategies have not yet been determined. Finally, there is concurrent evidence that iron supplementation of anaemic school-aged children reduces IDA and possibly improves neuropsychological outcomes.

SUMMARY

Interventions for prevention of iron deficiency should be prioritized in risk groups. However, the unclear long-term benefits and possible risk of adverse effects, particularly increased infections in developing countries, prompt further large-scale, double-blinded trials.