High-versus low-dose erythropoietin in extremely low birth weight infants. The European Multicenter rhEPO Study Group

Anemia of prematurity: how low is too low?

Anemia of prematurity (AOP) is a common condition with a well-described chronology, nadir hemoglobin levels, and timeline of recovery. However, the underlying pathophysiology and impact of prolonged exposure of the developing infant to low levels of hemoglobin remains unclear. Phlebotomy losses exacerbate the gradual decline of hemoglobin levels which is insidious in presentation, often without any clinical signs. Progressive anemia in preterm infants is associated with poor weight gain, inability to take oral feeds, tachycardia and exacerbation of apneic, and bradycardic events. There remains a lack of consensus on treatment thresholds for RBC transfusion which vary considerably. This review elaborates on the current state of the problem, its implication for the premature infant including association with subphysiologic cerebral tissue oxygenation, necrotizing enterocolitis, and retinopathy of prematurity. It outlines the impact of prophylaxis and treatment of anemia of prematurity and offers suggestions on improving monitoring and management of the condition.

Update on Erythropoiesis-Stimulating Agents Administered to Neonates for Neuroprotection

Erythropoiesis-stimulating agents (ESAs) such as erythropoietin and darbepoetin have been studied as red blood cell growth factors in preterm and term infants for more than 30 years. Recently, studies have focused on the potential neuroprotective effects of ESAs. In this review, we summarize preclinical animal models and recent clinical trials that provide evidence for ESAs as potential treatments to improve neurodevelopmental outcomes in preterm and term infants.

Early erythropoiesis-stimulating agents in preterm or low birth weight infants

BACKGROUND

Preterm infants have low plasma levels of erythropoietin (EPO), providing a rationale for the use of erythropoiesis-stimulating agents (ESAs) to prevent or treat anaemia and to provide neuro protection and protection against necrotising enterocolitis (NEC). Darbepoetin (Darbe) and EPO are currently available ESAs.

OBJECTIVES

To assess the effectiveness and safety of ESAs (erythropoietin (EPO) and/or Darbe) initiated early (before eight days after birth) compared with placebo or no intervention in reducing red blood cell (RBC) transfusions, adverse neurological outcomes, and feeding intolerance including necrotising enterocolitis (NEC) in preterm and/or low birth weight infants. Primary objective for studies that primarily investigate the effectiveness and safety of ESAs administered early in reducing red blood cell transfusions: To assess the effectiveness and safety of ESAs initiated early in reducing red blood cell transfusions in preterm infants. Secondary objectives: Review authors performed subgroup analyses of low (≤ 500 IU/kg/week) and high (> 500 IU/kg/week) doses of EPO and the amount of iron supplementation provided: none, low (≤ 5 mg/kg/d), and high (> 5 mg/kg/d). Primary objective for studies that primarily investigate the neuro protective effectiveness of ESAs: To assess the effectiveness and safety of ESAs initiated early in reducing adverse neurological outcomes in preterm infants. Primary objective for studies that primarily investigate the effectiveness of EPO or Darbe administered early in reducing feeding intolerance: To assess the effectiveness and safety of ESAs administered early in reducing feeding intolerance (and NEC) in preterm infants. Other secondary objectives: To compare the effectiveness of ESAs in reducing the incidence of adverse events and improving long-term neurodevelopmental outcomes.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), MEDLINE via PubMed (1966 to 10 March 2017), Embase (1980 to 10 March 2017), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 10 March 2017). We searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised and quasi-randomised controlled trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of early initiation of EAS treatment versus placebo or no intervention in preterm or low birth weight infants.

DATA COLLECTION AND ANALYSIS

We used the methods described in the Cochrane Handbook for Systematic Reviews of Interventions and the GRADE approach to assess the quality of evidence.

MAIN RESULTS

This updated review includes 34 studies enrolling 3643 infants. All analyses compared ESAs versus a control consisting of placebo or no treatment. Early ESAs reduced the risk of 'use of one or more [red blood cell] RBC transfusions' (typical risk ratio (RR) 0.79, 95% confidence interval (CI) 0.74 to 0.85; typical risk difference (RD) -0.14, 95% CI -0.18 to -0.10; I² = 69% for RR and 62% for RD (moderate heterogeneity); number needed to treat for an additional beneficial outcome (NNTB) 7, 95% CI 6 to 10; 19 studies, 1750 infants). The quality of the evidence was low. Necrotising enterocolitis was significantly reduced in the ESA group compared with the placebo group (typical RR 0.69, 95% CI 0.52 to 0.91; typical RD -0.03, 95% CI -0.05 to -0.01; I² = 0% for RR and 22% for RD (low heterogeneity); NNTB 33, 95% CI 20 to 100; 15 studies, 2639 infants). The quality of the evidence was moderate. Data show a reduction in 'Any neurodevelopmental impairment at 18 to 22 months' corrected age in the ESA group (typical RR 0.62, 95% CI 0.48 to 0.80; typical RD -0.08, 95% CI -0.12 to -0.04; NNTB 13, 95% CI 8 to 25. I² = 76% for RR (high heterogeneity) and 66% for RD (moderate); 4 studies, 1130 infants). The quality of the evidence was low. Results reveal increased scores on the Bayley-II Mental Development Index (MDI) at 18 to 24 months in the ESA group (weighted mean difference (WMD) 8.22, 95% CI 6.52 to 9.92; I² = 97% (high heterogeneity); 3 studies, 981 children). The quality of the evidence was low. The total volume of RBCs transfused per infant was reduced by 7 mL/kg. The number of RBC transfusions per infant was minimally reduced, but the number of donors to whom infants who were transfused were exposed was not significantly reduced. Data show no significant difference in risk of stage ≥ 3 retinopathy of prematurity (ROP) with early EPO (typical RR 1.24, 95% CI 0.81 to 1.90; typical RD 0.01, 95% CI -0.02 to 0.04; I² = 0% (no heterogeneity) for RR; I² = 34% (low heterogeneity) for RD; 8 studies, 1283 infants). Mortality was not affected, but results show significant reductions in the incidence of intraventricular haemorrhage (IVH) and periventricular leukomalacia (PVL).

AUTHORS' CONCLUSIONS

Early administration of ESAs reduces the use of red blood cell (RBC) transfusions, the volume of RBCs transfused, and donor exposure after study entry. Small reductions are likely to be of limited clinical importance. Donor exposure probably is not avoided, given that all but one study included infants who had received RBC transfusions before trial entry. This update found no significant difference in the rate of ROP (stage ≥ 3) for studies that initiated EPO treatment at less than eight days of age, which has been a topic of concern in earlier versions of this review. Early EPO treatment significantly decreased rates of IVH, PVL, and NEC. Neurodevelopmental outcomes at 18 to 22 months and later varied in published studies. Ongoing research should evaluate current clinical practices that will limit donor exposure. Promising but conflicting results related to the neuro protective effect of early EPO require further study. Very different results from the two largest published trials and high heterogeneity in the analyses indicate that we should wait for the results of two ongoing large trials before drawing firm conclusions. Administration of EPO is not currently recommended because limited benefits have been identified to date. Use of darbepoetin requires further study.

Early erythropoiesis-stimulating agents in preterm or low birth weight infants

BACKGROUND

Preterm infants have low plasma levels of erythropoietin (EPO), providing a rationale for the use of erythropoiesis-stimulating agents (ESAs) to prevent or treat anaemia and to provide neuro protection and protection against necrotising enterocolitis (NEC). Darbepoetin (Darbe) and EPO are currently available ESAs.

OBJECTIVES

To assess the effectiveness and safety of ESAs (erythropoietin (EPO) and/or Darbe) initiated early (before eight days after birth) compared with placebo or no intervention in reducing red blood cell (RBC) transfusions, adverse neurological outcomes, and feeding intolerance including necrotising enterocolitis (NEC) in preterm and/or low birth weight infants. Primary objective for studies that primarily investigate the effectiveness and safety of ESAs administered early in reducing red blood cell transfusions:To assess the effectiveness and safety of ESAs initiated early in reducing red blood cell transfusions in preterm infants. Secondary objectives:Review authors performed subgroup analyses of low (≤ 500 IU/kg/week) and high (> 500 IU/kg/week) doses of EPO and the amount of iron supplementation provided: none, low (≤ 5 mg/kg/d), and high (> 5 mg/kg/d). Primary objective for studies that primarily investigate the neuro protective effectiveness of ESAs:To assess the effectiveness and safety of ESAs initiated early in reducing adverse neurological outcomes in preterm infants. Primary objective for studies that primarily investigate the effectiveness of EPO or Darbe administered early in reducing feeding intolerance:To assess the effectiveness and safety of ESAs administered early in reducing feeding intolerance (and NEC) in preterm infants. Other secondary objectives:To compare the effectiveness of ESAs in reducing the incidence of adverse events and improving long-term neurodevelopmental outcomes.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), MEDLINE via PubMed (1966 to 10 March 2017), Embase (1980 to 10 March 2017), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 10 March 2017). We searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised and quasi-randomised controlled trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of early initiation of EAS treatment versus placebo or no intervention in preterm or low birth weight infants.

DATA COLLECTION AND ANALYSIS

We used the methods described in the Cochrane Handbook for Systematic Reviews of Interventions and the GRADE approach to assess the quality of evidence.

MAIN RESULTS

This updated review includes 34 studies enrolling 3643 infants. All analyses compared ESAs versus a control consisting of placebo or no treatment.Early ESAs reduced the risk of 'use of one or more [red blood cell] RBC transfusions' (typical risk ratio (RR) 0.79, 95% confidence interval (CI) 0.74 to 0.85; typical risk difference (RD) -0.14, 95% CI -0.18 to -0.10; I2 = 69% for RR and 62% for RD (moderate heterogeneity); number needed to treat for an additional beneficial outcome (NNTB) 7, 95% CI 6 to 10; 19 studies, 1750 infants). The quality of the evidence was low.Necrotising enterocolitis was significantly reduced in the ESA group compared with the placebo group (typical RR 0.69, 95% CI 0.52 to 0.91; typical RD -0.03, 95% CI -0.05 to -0.01; I2 = 0% for RR and 22% for RD (low heterogeneity); NNTB 33, 95% CI 20 to 100; 15 studies, 2639 infants). The quality of the evidence was moderate.Data show a reduction in 'Any neurodevelopmental impairment at 18 to 22 months' corrected age in the ESA group (typical RR 0.62, 95% CI 0.48 to 0.80; typical RD -0.08, 95% CI -0.12 to -0.04; NNTB 13, 95% CI 8 to 25. I2 = 76% for RR (high heterogeneity) and 66% for RD (moderate); 4 studies, 1130 infants). The quality of the evidence was low.Results reveal increased scores on the Bayley-II Mental Development Index (MDI) at 18 to 24 months in the ESA group (weighted mean difference (WMD) 8.22, 95% CI 6.52 to 9.92; I2 = 97% (high heterogeneity); 3 studies, 981 children). The quality of the evidence was low.The total volume of RBCs transfused per infant was reduced by 7 mL/kg. The number of RBC transfusions per infant was minimally reduced, but the number of donors to whom infants who were transfused were exposed was not significantly reduced. Data show no significant difference in risk of stage ≥ 3 retinopathy of prematurity (ROP) with early EPO (typical RR 1.24, 95% CI 0.81 to 1.90; typical RD 0.01, 95% CI -0.02 to 0.04; I2 = 0% (no heterogeneity) for RR; I2 = 34% (low heterogeneity) for RD; 8 studies, 1283 infants). Mortality was not affected, but results show significant reductions in the incidence of intraventricular haemorrhage (IVH) and periventricular leukomalacia (PVL).

AUTHORS' CONCLUSIONS

Early administration of ESAs reduces the use of red blood cell (RBC) transfusions, the volume of RBCs transfused, and donor exposure after study entry. Small reductions are likely to be of limited clinical importance. Donor exposure probably is not avoided, given that all but one study included infants who had received RBC transfusions before trial entry. This update found no significant difference in the rate of ROP (stage ≥ 3) for studies that initiated EPO treatment at less than eight days of age, which has been a topic of concern in earlier versions of this review. Early EPO treatment significantly decreased rates of IVH, PVL, and NEC. Neurodevelopmental outcomes at 18 to 22 months and later varied in published studies. Ongoing research should evaluate current clinical practices that will limit donor exposure. Promising but conflicting results related to the neuro protective effect of early EPO require further study. Very different results from the two largest published trials and high heterogeneity in the analyses indicate that we should wait for the results of two ongoing large trials before drawing firm conclusions. Administration of EPO is not currently recommended because limited benefits have been identified to date. Use of darepoetin requires further study.

Prophylactic Early Erythropoietin for Neuroprotection in Preterm Infants: A Meta-analysis

CONTEXT

Recombinant human erythropoietin (rhEPO) is a promising pharmacological agent for neuroprotection in neonates.

OBJECTIVE

To investigate whether prophylactic rhEPO administration in very preterm infants improves neurodevelopmental outcomes in a meta-analysis of randomized controlled trials (RCTs).

DATA SOURCES

Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched in December 2016 and complemented by other sources.

STUDY SELECTION

RCTs investigating the use of rhEPO in preterm infants versus a control group were selected if they were published in a peer-reviewed journal and reported neurodevelopmental outcomes at 18 to 24 months' corrected age.

DATA EXTRACTION

Data extraction and analysis followed the standard methods of the Cochrane Neonatal Review Group. The primary outcome was the number of infants with a Mental Developmental Index (MDI) <70 on the Bayley Scales of Infant Development. Secondary outcomes included a Psychomotor Development Index <70, cerebral palsy, visual impairment, and hearing impairment.

RESULTS

Four RCTs, comprising 1133 infants, were included in the meta-analysis. Prophylactic rhEPO administration reduced the incidence of children with an MDI <70, with an odds ratio (95% confidence interval) of 0.51 (0.31-0.81), P < .005. The number needed to treat was 14. There was no statistically significant effect on any secondary outcome.

CONCLUSIONS

Prophylactic rhEPO improved the cognitive development of very preterm infants, as assessed by the MDI at a corrected age of 18 to 24 months, without affecting other neurodevelopmental outcomes. Current and future RCTs should investigate optimal dosing and timing of prophylactic rhEPO and plan for long-term neurodevelopmental follow-up.

Early erythropoietin for preventing red blood cell transfusion in preterm and/or low birth weight infants

BACKGROUND

Low plasma levels of erythropoietin (EPO) in preterm infants provide a rationale for the use of EPO to prevent or treat anaemia.

OBJECTIVES

To assess the effectiveness and safety of early initiation of EPO or darepoetin (initiated before eight days after birth) in reducing red blood cell (RBC) transfusions in preterm and/orlow birth weight infants.

SEARCH METHODS

The Cochrane Library, MEDLINE, EMBASE, CINAHL, reference lists of identified trials and reviews, Pediatric Academic Societies Annual meetings 2000 to 2013 (Abstracts2View(TM)) and clinical trials registries (clinicaltrials.gov; controlled-trials.com; and who.int/ictrp) were searched in July 2013.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of early (< eight days of age) initiation of EPO treatment versus placebo or no intervention in preterm and/or low birth weightinfants.

DATA COLLECTION AND ANALYSIS

The methods of the Neonatal Cochrane Review Group were used.

MAIN RESULTS

The updated review includes 27 studies enrolling 2209 infants. One study enrolling infants at a mean age of > eight days and one duplicate publication were excluded. One new study using darepoetin was identified.Early EPO reduced the risk of the 'use of one or more RBC transfusions' (typical risk ratio (RR) 0.79, 95% confidence interval (CI) 0.73 to 0.85; typical risk difference (RD) -0.14, 95% CI -0.18 to -0.10; I(2) = 54% for both; number needed to treat to benefit (NNTB) 7, 95% CI 6 to 10; 16 studies, 1661 infants).The total volume of RBCs transfused per infant was reduced (typical mean difference (MD) 7 mL/kg, 95% CI -12 to - 2; I(2) = 63%; 7 studies, 581 infants). The number of RBC transfusions per infant was minimally reduced (typical MD -0.27, 95% CI -0.42 to -0.12; I(2) = 64%; 13 studies, 951 infants). The number of donors to whom the infants were exposed was significantly reduced (MD-0.54, 95% CI -0.89 to -0.20; I(2) = 0%; 3 studies, 254 infants).There was a non-significant increase in the risk of stage ≥ 3 retinopathy of prematurity (ROP) with early EPO (typical RR 1.37, 95% CI 0.87 to 2.17; I(2) = 0%; typical RD 0.03, 95% CI -0.01 to 0.06; I(2) = 29%; 7 studies, 801 infants). A post hoc analysis including all studies that reported on ROP stage ≥ 3, regardless of the age of the infant when EPO treatment was started, showed a significantly increased typical RR of 1.48 (95% CI 1.02 to 2.13; P = 0.04; I(2) = 0%) and typical RD of 0.03 (95% CI 0.00 to 0.06; P = 0.03; I(2) = 50%; 10 studies, 1303 infants) with a number needed to treat to harm (NNTH) of 33 (95% CI 17 to infinity). In an Italian study in which the authors compared the use of early intravenous EPO with subcutaneous EPO the overall incidence of stage ≥ 3 was 15%, similar to the incidence of 17% in the study by Romagnoli and co-workers.The rates for mortality and morbidities including intraventricular haemorrhage and necrotizing enterocolitis were not significantly changed by early EPO treatment. Neurodevelopmental outcomes at 18 to 22 months varied.

AUTHORS' CONCLUSIONS

Early administration of EPO reduces the use of RBC transfusions, the volume of RBCs transfused, and donor exposure after study entry. The small reductions are likely to be of limited clinical importance. Donor exposure is probably not avoided since all but one study included infants who had received RBC transfusions prior to trial entry. In this update there was no significant increase in the rate of ROP (stage ≥ 3) for studies that initiated EPO treatment at less than eight days of age. In a post hoc analysis including all studies that reported on ROP stage ≥ 3 regardless of age at initiation of treatment there was an increased risk of ROP. The rates for mortality and morbidities including intraventricular haemorrhage and necrotizing enterocolitis were not significantly changed by early EPO treatment. Neurodevelopmental outcomes at 18 to 22 months vary in the studies published to date. Ongoing research should deal with the issue of ROP and evaluate current clinical practice that will limit donor exposure. Due to the limited benefits and the possibly increased risk of ROP, administration of EPO is not recommended. Darbepoetin requires further study. The possible neuroprotective role of EPO in neonates will be reviewed in separate Cochrane reviews.

Early erythropoietin for preventing red blood cell transfusion in preterm and/or low birth weight infants

BACKGROUND

Low plasma levels of erythropoietin (EPO) in preterm infants provide a rationale for the use of EPO to prevent or treat anaemia.

OBJECTIVES

To assess the effectiveness and safety of early initiation of EPO in reducing red blood cell (RBC) transfusions in preterm and/or low birth weight infants.

SEARCH METHODS

The Cochrane Central Register of Controlled Trials (The Cochrane Library), MEDLINE, EMBASE, CINAHL, abstracts from scientific meetings published in Pediatric Research and reference lists of identified trials and reviews were searched through July 2009. Searches were repeated in March 2012 including searches of Pediatric Academic Societies Annual meetings 2000 to 2012 (Abstracts2View(TM)) and clinical trials registries (clinicaltrials.gov; controlled-trials.com; and who.int/ictrp).

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of early (< eight days of age) initiation of EPO treatment versus placebo or no intervention in preterm and/or low birth weight neonates.

DATA COLLECTION AND ANALYSIS

Data collection and analysis were accomplished using the methods of the Neonatal Cochrane Review Group.

MAIN RESULTS

The May 2012 update did not identify any new studies for inclusion. A number of randomised controlled trials were excluded as they compared one EPO dosing regimen with another, did not provide the numbers of infants randomised to the EPO and the placebo group, or the dose of EPO was not stated. The update includes 27 studies that enrolled 2293 preterm infants. Early EPO reduced the risk of the "use of one or more RBC transfusions" [typical risk ratio (RR); 0.80 (95% confidence interval (CI) 0.75 to 0.86); typical risk difference (RD) -0.13, (95% CI -0.17 to -0.09); number needed to benefit (NNTB) = eight, (95% CI 6 to 11); 16 studies, 1,825 infants].There was moderate heterogeneity for this outcome [RR (P = 0.004; I(2) = 56.7%); RD (P = 0.003; I(2) = 56.0%)].A total of six studies enrolling 515 infants reported on the total volume of red blood cells transfused per infant. The significant typical mean difference (MD) was a reduction of 6 mL/kg of blood transfused (mL/kg) per infant (95% CI -11 to - 1). There was moderate heterogeneity for this outcome (P = 0.02; I(2) = 63.0%). The results from 14 studies enrolling 1131 infants reported on the number of red blood cell transfusions per infant. The significant typical MD for number of red blood cell transfusions per infant was -0.33, (95% CI -0.48 to -0.18). There was high heterogeneity for this outcome (P = 0.00001, I(2) = 78%). Two studies enrolling 188 infants reported on the number of donors to whom the infant was exposed; the MD was significantly reduced -0.63, (-1.07 to -0.19). There was no heterogeneity for this outcome (P = 0.59; I(2) = 0%).There was a significant increase in the risk of stage ≥ 3 retinopathy of prematurity (ROP) in the early EPO group [typical RR; 1.65, (95% CI 1.12 to 2.43); typical RD; 0.05 (95% CI 0.01 to 0.08); number needed to harm (NNTH); 20, (95% CI 13 to 100); eight studies, 984 infants]. There was no heterogeneity for this outcome for RR (P = 0.87; I(2) = 0%), but there was moderate heterogeneity for RD (P = 0.006; I(2) = 65%). The rates for mortality and other neonatal morbidities were not significantly changed by early EPO treatment nor were neurodevelopmental outcomes at 18 to 22 months in the small number of infants tested to-date.

AUTHORS' CONCLUSIONS

Early administration of EPO reduces the use of RBC transfusions and the volume of RBCs transfused. These small reductions are of limited clinical importance. Donor exposure is probably not avoided since most studies included infants who had received RBC transfusions prior to trial entry. There was a significant increase in the rate of ROP (stage ≥ 3). Early EPO does not significantly decrease or increase any of the other important adverse outcomes. Ongoing research should deal with the issue of ROP and evaluate the current clinical practice that will limit donor exposure. Due to the limited benefits and the increased risk of ROP, early administration of EPO is not recommended. Evidence is lacking for the possible neuro protective role of EPO in preterm infants. This topic will be reviewed in separate Cochrane reviews for preterm and term and late preterm infants.

A randomized, masked study of weekly erythropoietin dosing in preterm infants

OBJECTIVE

To compare reticulocyte responses of once-per-week erythropoietin (EPO) dosing with 3-times-a-week dosing in preterm infants.

STUDY DESIGN

Infants weighing ≤ 1500 g and ≥ 7 days of age were randomized to once-per-week EPO, 1200 U/kg/dose, or 3-times-a-week EPO, 400 U/kg/dose, subcutaneously for 4 weeks, along with iron and vitamin supplementation. Complete blood counts, absolute reticulocyte counts (ARCs), transfusions, phlebotomy losses, and adverse events were recorded.

RESULTS

Twenty preterm infants (962 ± 55 g, 27.9 ± 0.4 weeks, 17 ± 3 days of age) were enrolled. Groups were similar at baseline. Infants in both groups had increased ARCs, which were similar between treatment groups at the start and end of 4 weeks. Hematocrit remained stable, and similar numbers of transfusions were administered. No adverse effects of either dosing schedule were noted.

CONCLUSIONS

Preterm infants respond to weekly EPO by increasing ARCs and maintaining hematocrit. We speculate that once-per-week EPO dosing might be beneficial to preterm infants requiring increased erythropoiesis.

Red blood cell transfusions in newborn infants: Revised guidelines

In general, health care professionals taking care of high risk infants in neonatal intensive care units have become more restrictive in their use of red blood cell transfusion over the past 10 years. The present statement is intended for those caring for high risk newborn infants (preterm to one month of age). The objectives of this statement are to provide guidelines to reduce the incidence of anemia in preterm and term infants, to identify strategies to decrease the need for red blood cell transfusions and to limit donor exposure in this population. Recommendations for red blood cell transfusions are included.

Comparison between one and three doses a week of recombinant erythropoietin in very low birth weight infants

OBJECTIVE

To compare transfusion requirements and erythropoietic response in preterms between schedules of rEPO administration once or three times per week, using the same weekly dose.

STUDY DESIGN

Prospective, randomized trial including infants weighing <1500 g at birth and/or were 32 weeks' gestation: Group 1 (60 infants) received subcutaneous rEPO at 250 units kg(-1) per dose, three times weekly for 6 weeks; Group 2 (59 infants), at 750 units kg(-1) per dose, once weekly for 6 weeks. Efficacy was evaluated based on the transfusion requirement, hemoglobin changes, reticulocyte counts, serum transferrin receptor (sTfR) and serum ferritin. The frequency of adverse effects was registered in both groups.

RESULT

A total of 13 infants were transfused in each group (relative risk: 0.98; 95% confidence interval: 0.4 to 2.3). Phlebotomy loss and red blood cell transfusion volumes received were similar in both groups. Hemoglobin levels were lower at end of study in Group 2 (10.6±1.5 g dl(-1) versus 11.5±1.4 g dl(-1); P<0.003). At end of study, reticulocyte counts and sTfR values increased and serum ferritin values decreased, without significant differences between the two groups. Incidence of complications was similar in both groups.

CONCLUSION

The once-weekly rEPO schedule for very low birth weight infants proved as effective as the three-times-weekly schedule, in relation to erythropoietic stimulus and transfusion requirement.

Anemia in the preterm infant: erythropoietin versus erythrocyte transfusion--it's not that simple

Since the late 1980s recombinant human erythropoietin (r-EPO) has been studied as an alternative to packed red blood cell (RBC) transfusion for the treatment of anemia of prematurity in very low birth weight infants. Initial trials and reports focused on r-EPO's ability to prevent or treat anemia of prematurity with the goal of eliminating RBC transfusion but achieved limited success. New concerns about the safety of r-EPO administration have emerged. Past cost-benefit analyses of r-EPO administration versus transfusion for the treatment of anemia of prematurity have been nearly balanced. Autologous transfusion, blood-sparing technologies, changes in RBC transfusion technique and safety, and further elucidation of the risk-benefit ratio of r-EPO therapy may change the cost-benefit analysis.

Anemia in the preterm infant: erythropoietin versus erythrocyte transfusion--it's not that simple

Since the late 1980s recombinant human erythropoietin (r-EPO) has been studied as an alternative to packed red blood cell (RBC) transfusion for the treatment of anemia of prematurity in very low birth weight infants. Initial trials and reports focused on r-EPO's ability to prevent or treat anemia of prematurity with the goal of eliminating RBC transfusion but achieved limited success. New concerns about the safety of r-EPO administration have emerged. Past cost-benefit analyses of r-EPO administration versus transfusion for the treatment of anemia of prematurity have been nearly balanced. Autologous transfusion, blood-sparing technologies, changes in RBC transfusion technique and safety, and further elucidation of the risk-benefit ratio of r-EPO therapy may change the cost-benefit analysis.

Current controversies in the management of the anemia of prematurity

Preterm infants, especially those with extremely low birth weight (ELBW) are exposed to frequent blood draws as part of their care in the neonatal intensive care unit. ELBW infants develop the anemia of prematurity (AOP), a hypo-proliferative anemia marked by inadequate production of erythropoietin (Epo). Treatment of AOP includes red blood cell transfusions, which are given to preterm infants based on indications and guidelines (hematocrit/hemoglobin levels, ventilation and oxygen need, apneas and bradycardias, poor weight gain) that are relatively non-specific. In this article we review recent studies evaluating transfusion guidelines, discuss ways to decrease phlebotomy losses and examine the use of red cell growth factors such as Epo in preventing and treating anemia in preterm infants.

Pathophysiology of Anemia During the Neonatal Period, Including Anemia of Prematurity

This review summarizes the current thinking about the causes of anemia universally experienced by preterm infants in the early postnatal weeks. In addition to describing developmentally determined physiologic processes contributing to anemia of prematurity, this review discusses clinically important nonphysiologic contributors to anemia experienced by preterm infants during the neonatal period. Chief among these and an important contributor to the need for red blood cell transfusions is the heavy laboratory phlebotomy loss sustained shortly after birth, when neonatal cardiorespiratory illness is most severe. Understanding and recognizing the physiologic and nonphysiologic processes contributing to anemia encountered in early postnatal life is important in knowing which treatment and prevention modalities are likely to be most effective in different clinical situations. The evaluation of rare and uncommon acquired and genetic causes of anemia in newborns are not covered in this review.

The use of blood products in perinatal medicine

Fetal and neonatal medicine is a field with many new procedures and techniques. An increasing number of centres worldwide give intrauterine transfusions, which are considered to be standard-of-care treatment for severe fetal anaemia. The survival of very prematurely born neonates, in particular of a gestational age of <28 weeks, has greatly improved over the last decade but almost all these children need transfusions. Although in many cases such blood transfusions are life saving, randomized, controlled studies investigating appropriate indications, transfusion volume and type of blood product have not been performed. Most of the protocols used are expert based.

Is there a role for erythropoietin in neonatal medicine?

Since it was first cloned in 1985, the therapeutic potential of recombinant human erythropoietin in the neonatal hyporegenerative anaemias has been studied-the anaemia of prematurity and haemolytic disease of the newborn. Between 60% and 100% of preterm infants are transfused before three weeks of age, a large proportion receiving more than one transfusion. Blood transfusions are currently also the mainstay of treatment for the hyporegenerative anaemia encountered in neonates with Rhesus disease. Sometimes the situation is complicated by the religious beliefs of the parents. Blood transfusions are associated with numerous risks, from transmission of infection to local injury, and in an effort to minimize these risks Neonatologists have looked to recombinant erythropoietin. Despite an extensive number of studies, there is as yet no clear consensus as to whether the use of recombinant erythropoietin in Neonatal medicine minimizes the need for blood transfusions without risk to the neonate. In this article we review the evidence for and against the use of recombinant erythropoietin in Neonatal medicine.

Effect of hemoglobin on transfusion and neonatal adaptation in extremely low-birthweight infants

BACKGROUND

The aim of the present paper was to investigate the effect of initial hemoglobin level on red blood cell transfusion and neonatal adaptation in extremely low-birthweight (ELBW) infants.

METHODS

Subjects consisted of 54 ELBW infants admitted to level III neonatal intensive care unit between 1995 and 2000, and divided into two groups based on hemoglobin level at birth. High hemoglobin was defined as hemoglobin > or =15.0 g/dL.

RESULTS

There were no significant differences in gestational age and birthweight between the high hemoglobin group (n = 28) and low hemoglobin group (n = 26). The high hemoglobin group had decreased probability of requiring red blood cell transfusion (P < 0.05) and number of red blood cell transfusions (P < 0.05). Mortality rate in the low hemoglobin group was significantly higher compared with the high hemoglobin group (P = 0.03). In the high hemoglobin group, blood pressures during the first 24 h were significantly higher (P < 0.05) and the risk of intraventricular hemorrhage was significantly lower (P = 0.04) compared with the low hemoglobin group. The predictive variables, initial hemoglobin level (odds ratio 1.93 [decrease by 1 g/dL]) and intraventricular hemorrhage > or =III (odds ratio 21.76 [positive]) were found to be most predictive for death on logistic regression.

CONCLUSION

High hemoglobin level at birth is associated with a significantly reduced requirement for red blood cell transfusion and might contribute to stabilization of blood pressure, and thus reduce mortality and the risk of severe intraventricular hemorrhage.

Role of hypoxia and cAMP in the transdifferentiation of human fetal cardiac fibroblasts: implications for progression to scarring in autoimmune-associated congenital heart block

OBJECTIVE

Identification of isolated congenital heart block (CHB) predicts, with near certainty, the presence of maternal anti-SSA/Ro antibodies; however, the 2% incidence of CHB in first offspring of anti-SSA/Ro+ mothers, 20% recurrence in subsequent pregnancies, and discordance in identical twins suggest that an environmental factor amplifies the effect of the antibody. Accordingly, this study was carried out to explore the hypothesis that hypoxia potentiates a profibrosing phenotype of the fetal cardiac fibroblast.

METHODS

Evidence of an effect of hypoxia was sought by immunohistologic evaluation of CHB-affected fetal heart tissue and by determination of erythropoietin levels in cord blood. The in vitro effect of hypoxia on gene expression and phenotype in fibroblasts derived from fetal hearts and lungs was investigated by Affymetrix arrays, quantitative polymerase chain reaction (PCR), immunofluorescence, and immunoblotting.

RESULTS

In vivo hypoxic exposure was supported by the prominent intracellular fibroblast expression of hypoxia-inducible factor 1alpha in conduction tissue from 2 fetuses in whom CHB led to death. The possibility that hypoxia was sustained was suggested by significantly elevated erythropoietin levels in cord blood from CHB-affected, as compared with unaffected, anti-SSA/Ro-exposed neonates. In vitro exposure of cardiac fibroblasts to hypoxia resulted in transdifferentiation to myofibroblasts (a scarring phenotype), as demonstrated on immunoblots and immunofluorescence by increased expression of smooth muscle actin (SMA), an effect not seen in lung fibroblasts. Hypoxia-exposed cardiac fibroblasts expressed adrenomedullin at 4-fold increased levels, as determined by Affymetrix array, quantitative PCR, and immunofluorescence, thus focusing attention on cAMP as a modulator of fibrosis. MDL12,330A, an adenylate cyclase inhibitor that lowers the levels of cAMP, increased expression of fibrosis-related proteins (mammalian target of rapamycin, SMA, plasminogen activator inhibitor type 1, and type I collagen), while the cAMP activator forskolin attenuated transforming growth factor beta-elicited fibrosing end points in the cardiac fibroblasts.

CONCLUSION

These findings provide evidence that hypoxia may amplify the injurious effects of anti-SSA/Ro antibodies. Modulation of cAMP may be a key component in the scarring phenotype. Further assessment of the susceptibility of cardiac fibroblasts to cAMP modulation offers a new research direction in CHB.

Umbilical cord milking reduces the need for red cell transfusions and improves neonatal adaptation in infants born at less than 29 weeks' gestation: a randomised controlled trial

OBJECTIVE

To investigate the effects of umbilical cord milking on the need for red blood cell (RBC) transfusion and morbidity in very preterm infants.

PATIENTS AND METHODS

40 singleton infants born between 24 and 28 weeks' gestation were randomly assigned to receive umbilical cord clamped either immediately (control group, n = 20) or after umbilical cord milking (milked group, n = 20). Primary outcome measures were the probability of not needing transfusion, determined by Kaplan-Meier analysis, and the total number of RBC transfusions. Secondary outcome variables were haemoglobin value and blood pressure at admission.

RESULTS

There were no significant differences in gestational age and birth weight between the two groups. The milked group was more likely not to have needed red cell transfusion (p = 0.02) and had a decreased number (mean (SD)) of RBC transfusions (milked group 1.7 (3.0) vs controls 4.0 (4.2); p = 0.02). The initial mean (SD) haemoglobin value was higher in the milked group (165 (14) g/l) than in the controls (141 (16) g/l); p<0.01). Mean (SD) blood pressure at admission was significantly higher in the milked group (34 (9) mm Hg) than in the controls 28 (8) mm Hg; p = 0.03). There was no significant difference in mortality between the groups. The milked group had a shorter duration of ventilation or supplemental oxygen than the control group.

CONCLUSION

Milking the umbilical cord is a safe procedure, reducing the need for RBC transfusions, and the need for circulatory and respiratory support in very preterm infants.

Prediction of transfusions in extremely low-birthweight infants in the erythropoietin era

BACKGROUND

The purpose of the present paper was to detect the clinical factors most predictive of red blood cell (RBC) transfusion in extremely low-birthweight (ELBW) infants in the recombinant human erythropoietin era.

METHODS

Between 1995 and 2000, 66 ELBW infants were admitted to a level III neonatal intensive care unit. Fifty-four of 66 infants were eligible for enrollment in the present study. Infants were treated with erythropoietin 200 IU/kg per dose s.c. twice a week with 4-6 mg/kg per day iron supplement.

RESULTS

The mean gestational age and birthweight were 26.5 +/- 2.1 weeks and 776 +/- 134 g, respectively. Ten of 54 ELBW infants (18.5%) died during the first 21 days. Eight of 10 dead infants (80.0%) and 27 of 44 surviving infants (61.4%) received one or more RBC transfusions. The overall requirement for RBC transfusions in the surviving infants was 3.0 +/- 3.2 per infant/hospital course (range: 0-9) . There were significant differences in gestational weeks, birthweight, initial hemoglobin value, 5 min Apgar score, phlebotomy loss, phlebotomy loss/birthweight, duration of mechanical ventilation, duration of oxygen supplement, and incidence of both intraventricular hemorrhage and chronic lung disease between the transfused and non-transfused group. The predictive variables, initial hemoglobin level (odds ratio [OR] 2.61; 1 g/dL), birthweight (OR 3.00; 100 g), and gestational week (OR 1.89; 1 week), were found to be most predictive for transfusion on logistic regression analysis.

CONCLUSION

ELBW infants are still the population at greatest risk for repeated blood transfusions after introduction of erythropoietin treatment. If labor develops, it is often impossible to extend the pregnancy period, therefore efforts should be made to increase hemoglobin level at birth.

Effects of a combined therapy of erythropoietin, iron, folate, and vitamin B12 on the transfusion requirements of extremely low birth weight infants

OBJECTIVES

Erythropoietin is frequently administered to premature infants to stimulate erythropoiesis. The primary goal of erythropoietin therapy is to reduce transfusions, but the efficacy of erythropoietin has not been convincingly demonstrated in this regard. The aim of this trial was to investigate whether combined administration of vitamin B12, folic acid, iron, and erythropoietin could decrease transfusion requirements in extremely low birth weight infants.

PATIENTS AND METHODS

In a randomized, controlled trial, extremely low birth weight infants with a birth weight < or = 800 g and a gestational age < or = 32 weeks were randomly assigned to a group receiving combination treatment or a control arm.

RESULTS

The treatment increased levels of folate in red blood cells, vitamin B12, ferritin, transferrin receptor levels in plasma, and reticulocyte counts. The proportion of infants requiring no transfusions was lower in the treatment group (38%) as compared with controls (5%). The treatment group and the need for mechanical ventilation were independent predictors of the number of transfusions in multiple regression analysis. Cox regression analysis indicated that combined therapy resulted in a 79% risk reduction for any transfusion.

CONCLUSION

Combined treatment with erythropoietin, intravenous iron, folate, and vitamin B12 during the first weeks reduces the need for transfusion in extremely low birth weight infants.

Early erythropoietin for preventing red blood cell transfusion in preterm and/or low birth weight infants

BACKGROUND

Hematocrit falls after birth in preterm infants due to physiological factors and blood letting. Low plasma levels of erythropoietin (EPO) in preterm infants provide a rationale for the use of EPO to prevent or treat anemia.

PRIMARY OBJECTIVE

To assess the effectiveness and safety of early initiation of EPO (initiated before eight days after birth) in reducing red blood cell transfusions in preterm and/or low birth weight infants.

SECONDARY OBJECTIVES

Subgroup analyses of low (< 500 IU/kg/week) and high (> 500 IU/kg/week) doses of EPO and, within these subgroups, analyses of the use of low (< 5 mg/kg/day) and high (> 5 mg/kg/day) doses of supplemental iron, in reducing red blood cell transfusions in these infants.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE, EMBASE, CINAHL, abstracts from scientific meetings published in Pediatric Research and reference lists of identified trials and reviews were searched in November 2005. No language restrictions were applied.

SELECTION CRITERIA

Randomised or quasi-randomized controlled trials of early initiation of EPO treatment (started before 8 days of age) vs. placebo or no intervention in preterm (< 37 weeks) and/or low birth weight (< 2500 g) neonates. For inclusion, the studies needed to provide information on at least one outcome of interest.

DATA COLLECTION AND ANALYSIS

Data were abstracted by the two authors on pre-tested data collection forms. Data were entered by one review author (AO) and checked for accuracy by the other (SA). Data were analysed using RevMan 4.2.8. The statistical methods included 'typical' relative risk (RR), risk difference (RD), number needed to treat to benefit (NNTB) and needed to treat to harm (NNTH) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes reported with their 95% confidence intervals (CI). A fixed effects model was used for meta-analyses. Heterogeneity tests, including the I(-)squared (I(2)) statistic, were performed to assess the appropriateness of pooling the data.

MAIN RESULTS

Twenty-three studies enrolling 2074 preterm infants in 18 countries were included in the review. All studies except one applied transfusion guidelines. The quality of the trials varied. Most trials were of small sample size. Only one study clearly stated that infants were excluded if they had received red blood cell transfusion prior to study entry (Arif 2005). A total of 16 studies, including 1825 infants reported on the primary outcome of "use of one or more red cell transfusions". The summary estimates were significant [typical RR; 0.80 (95% CI 0.75, 0.86); typical RD; -0.13 (95% CI -0.17, -0.09); typical NNTB; 8 (95% CI 6, 11)]. There was statistically significant heterogeneity [for RR (p< 0.004), I(2) = 56.7%; for RD (p = 0.003), I(2 ) = 56.0%]. Similar results were obtained in secondary analyses based on different combinations of high doses of EPO and high and low iron supplementation. There were insufficient data to draw conclusions for low doses EPO in combination with high or low dose of iron. Two studies (n = 188) reported a significant reduction in the number of donors to whom the infant was exposed [typical WMD; -0.63 (95% CI -1.07, -0.19)]. A significant reduction in the total volume (ml/kg) of blood transfused per infant [typical WMD; -6 ml (95% CI -1, -11)] and in the number of transfusions per infant [typical WMD -0.27 (95% CI -0.12, -0.42 )] was noted. There was a significant increase in the risk of stage > 3 retinopathy of prematurity (ROP) in the EPO group [typical RR; 1.71 (95% CI 1.15, 2.54); typical RD; 0.05 (95% CI 0.01, 0.09); NNTH; 20 (95% CI 11, 100)]. The non-significant results for ROP (any stage reported) showed a similar trend. The increased risk for ROP may be associated with use of higher doses of supplemental of iron in the EPO group than in the control group. The rates for mortality, sepsis, intraventricular haemorrhage, periventricular leukomalacia, necrotizing enterocolitis, bronchopulmonary dysplasia, neutropenia, hypertension, length of hospital stay or long-term neurodevelopmental outcomes were not significantly change by the administration of EPO.

AUTHORS' CONCLUSIONS

Early administration of EPO reduces the use one or more red blood cell transfusions, the volume of red blood cells transfused, and the number of donors and transfusions the infant is exposed to following study entry. The small reductions are of limited clinical importance. Any donor exposure is likely not avoided as most studies included infants, who had received red cell transfusions prior to trial entry. There was a significant increase in the rate of ROP (stage >3). Animal data and observational studies in humans support a possible association between treatment with EPO and the development of ROP. EPO does not significantly decrease or increase any of the other important neonatal adverse outcomes including mortality. The incidence of ROP should be ascertained in the studies that have already been conducted but did not report on this outcome. Any ongoing research should deal with the issue of ROP and evaluate the current clinical practice that will limit donor exposure through satellite units. Research efforts should focus on limiting donor exposure (to as few donors as possible) during the first few days of life in sick neonates, when red blood cell transfusions are most likely to be required and cannot be prevented by early (or late) EPO treatment. Due to the limited benefits and the increased risk of ROP, early administration of EPO is not recommended.

Stepping up versus standard doses of erythropoietin in preterm infants: a randomized controlled trial

In this study, it is hypothesized that a planned increase in the dose of recombinant human erythropoietin (rh-EPO) can prevent transfusion in very low birth weight infants. Two different regimens of rh-EPO were administrated, one consisting in increasing dosage up to 5000 U/kg/wk, according to the individual reticulocytes response, and the second in a standard therapy of 1250 U/kg/wk. Fifty-one infants participated. Despite a significant higher reticulocytosis, the study was prematurely terminated due to the results of an interim analysis showing that transfusion was not avoided by increasing the rh-EPO. No significant differences were found between the two regimens concerning transfusion rate, volume transfused, gain in weight, and adverse effects. Progressive titration of rh-EPO to improve the biological response does not leave premature infants free of transfusion.

Erythropoietin and prematurity--where do we stand?

Erythropoietin (EPO) treatment for anemia of prematurity is still controversial. Large multicentric trials demonstrate that administration of EPO+Fe cannot prevent early transfusions, particularly in very low birth weight newborns and in infants with severe neonatal diseases, but may have some beneficial effect to prevent late transfusions. Current treatment of anemia of prematurity should be multifactorial trying to minimize all causes that reduce erthrocytic mass (phlebotomies, use of noninvasive procedures) and promoting all factors that increase it (placental transfusion, adequate nutrition support). To evaluate the real impact of EPO treatment it is mandatory to follow similar transfusion protocols for preterm infants in all the studies. The aim of EPO+Fe administration should be to avoid new late transfusions in very low birth weight preterm infants or to prevent the first transfusion after the second week of life in less immature premature with the objective of reducing the number of donors rather than the number of transfusions. We have limited the use of EPO+Fe to infants <30 weeks gestational age and birth weight <or=1250 g as well as to infants weighing 1250-1500 g with initial severe disease. The comparison of outcomes before (28 months period with EPO+Fe treatment to all premature <or=32 weeks gestational age) and after 20 months of implementation of the new protocol showed a significant decrease in EPO+Fe treatment candidates (40.3% vs. 85.9%, P<0.001) without changes in the percentage of transfusions in both periods. Therefore if EPO treatment is to be given it should be limited to preterm infants with a birth weight <1000 g or those of 1000-1250 g associated with risk factors for blood transfusion. It should be started at 3-7 days of life at doses of 250 U/kg subcutaneously, three times a week, for 4-6 weeks depending on gestational age with oral iron 2-12 mg/kg/day to keep ferritin levels greater than 100 ng/mL.

Single-dose darbepoetin administration to anemic preterm neonates

OBJECTIVE

Darbepoetin is longer acting and more potent than recombinant erythropoietin (rEpo). In certain situations, preterm neonates might benefit from rEpo, and for such patients darbepoetin would require fewer doses at a lower cost. However, the proper dose and dosing interval have not been established.

STUDY DESIGN

We performed a prospective trial in two level III Neonatal Intensive Care Units. Patients <32 weeks gestation at birth, with a birth weight (BW) <1500 g, were eligible for participation if they were >21-days-old and had a hemoglobin (Hgb) concentration </or=10.5 g/dl. In all, 12 were to receive a single subcutaneous (s.c.) dose at either 1 or 4 microg/kg. Once before the dose was given, and at two preset intervals after, blood was obtained for immature reticulocyte fraction (IRF) and absolute reticulocyte count (ARC). Once before and at four preset intervals after, blood was obtained for pharmacokinetic studies.

RESULTS

The 12 subjects had BWs of 1129+/-245 g (mean+/-SD), were 29.2+/-1.2 weeks gestation at delivery, and were 43+/-12 days old with an Hgb concentration of 9.6+/-1.0 g/dl when the darbepoetin was given. Six received 1 microg/kg and six 4 microg/kg. The IRF increased (p<0.05) as did the ARC (p<0.05). The increases in IRF were somewhat greater among the 4 microg/kg recipients (P=0.06). The highest recorded concentrations of drug occurred 6 to 12 hours after administration. The combined 6 and 12 hours values were 185+/-106 mU/ml in the 1 microg/kg group vs 597+/-238 in the 4 microg/kg group (p<0.002). The t(1/2) was 26 hours (range 10 to 50). The biovailability-normalized clearance was 19 ml/hour/kg (range 5 to 54).

CONCLUSIONS

A single s.c. dose of darbepoetin given to preterm neonates accelerated effective erythropoiesis. The pharmacodynamic and pharmacokinetic findings suggest that darbepoetin dosing in neonates would require a higher unit dose/kg and a shorter dosing interval than are generally used for anemic adults.

Potential for protection and repair following injury to the developing brain: a role for erythropoietin?

Perinatal brain injury is a major contributor to perinatal morbidity and mortality, and a considerable number of these children will develop long term neurodevelopmental disabilities. Despite the severe clinical and socio-economic significance and the advances in neonatal care over the past twenty years, no therapy yet exists that effectively prevents or ameliorates detrimental neurodevelopmental effects in cases of perinatal/neonatal brain injury. Our objective is to review recent evidence in relation to the pervading hypothesis for targeting time-dependent molecular and cellular repair mechanisms in the developing brain. In addition we review several potential neuroprotective strategies specific to the developing nervous system, with a focus on erythropoietin (Epo) because of its potential role in protection as well as repair.

Effect of short-term erythropoietin therapy in anemic premature infants

OBJECTIVE

To determine the effectiveness of a 10-day subcutaneous erythropoietin (rHuEpo) course of 300 units per kg per dose plus oral iron compared to oral iron alone in anemic infants during their convalescent phase of illness.

STUDY DESIGN

Prospective, randomized trial performed at a 40-bed, teaching, referral, level III, neonatal intensive care unit. Infants with a gestational age at birth of less than 32 weeks, hematocrit of less than or equal to 28% with a corrected reticulocyte count of less than or equal to 5%, postconceptual age of less than 48 weeks or 5 months chronological age, and a diagnosis of anemia of prematurity were considered for inclusion. Major outcome parameters included hematocrit, corrected reticulocyte count and red cell transfusion requirements.

RESULTS

A total of 60 infants were enrolled (n=30 per group). Infants randomized to rHuEpo had a significantly higher post-treatment hematocrit and corrected reticulocyte count than infants in the iron only group (p<0.001). There was a trend towards fewer red cell requirements in the rHuEpo group.

CONCLUSIONS

The rHuEpo regimen studied here was associated with an acute improvement in hematocrit and corrected reticulocyte counts. This study did not demonstrate a statistically significant decrease in transfusion therapy, in part related to increased subsequent use of rHuEpo in the control group. Taken together, these data demonstrate that this regimen can effectively treat anemia in convalescent premature infants.

Does erythropoietin protect the preterm brain?

There is a high incidence of hypoxic-ischaemic brain injury and intraventricular haemorrhage in newborn infants, particularly those born preterm. Many die during the newborn period or suffer permanent neurodevelopmental handicaps. Hypoxic brain injury develops over several hours and could potentially be influenced by intervention. At present, no drug exists that effectively prevents infant brain injury or ameliorates detrimental neurodevelopmental effects. The hypothesis is put forward that systemic administration of recombinant human erythropoietin positively affects the neurodevelopmental outcome of high risk preterm infants affected by brain injury. A multicentre, randomised, placebo controlled study is proposed to prospectively test this hypothesis.

Haemodynamic effects of erythrocyte transfusion in preterm infants

The aim of the study was to assess the short-term cardiorespiratory effects of a standard red cell transfusion in very low birth weight (< 1500 g) infants undergoing intensive care. A total of 37 infants (birth weight 920 +/- 230 g, gestational age 27.8 +/- 2.1 weeks, age at study 6.1 +/- 3.9 days) with indwelling arterial lines were studied when 10 ml/kg of packed donor red cells were transfused based on clinical judgment. Infants with patent ductus arteriosus and/or inotropic treatment were excluded from the study. Oxygen saturation, left ventricular output, stroke volume, systolic, diastolic and mean arterial pressure, heart rate, and capillary refill time were assessed immediately prior to the transfusion and within an hour after the transfusion was completed. Capillary refill time after the transfusion was significantly shorter than prior to the transfusion (2.1 +/- 0.9 versus 2.4 +/- 1.0 s, P = 0.033). Left ventricular output, stroke volume and arterial pressures remained unaltered. Oxygen saturation after the transfusion was lower than before the transfusion (94.0 +/- 3.8 versus 95.3 +/- 2.5%, P = 0.014) despite unaltered oxygen supply.

CONCLUSION

the data suggest that although a red cell transfusion of 10 ml/kg may marginally improve peripheral perfusion, it does not influence cardiac output and arterial blood pressure in normotensive preterm infants. It may, however, cause a transient decrease in oxygen saturation.

Effect of beginning recombinant erythropoietin treatment within the first week of life, among very-low-birth-weight neonates, on "early" and "late" erythrocyte transfusions: a meta-analysis

OBJECTIVES

Erythrocyte transfusions to neonates can be categorized as "early" if given during the first 3 weeks of life and "late" if given thereafter. We used a meta-analysis to determine whether recombinant erythropoietin (rEpo) administration to very-low-birth-weight (VLBW, <1500 g) neonates, beginning in the first week of life, reduces either "early" or "late" transfusions.

STUDY DESIGN AND METHODS

Studies that used a randomized, placebo-controlled, double-masked design were deemed acceptable. We identified 12 acceptable, relevant, clinical trials. Additional data not provided in the publications were obtained from two of the authors.

RESULTS

The acceptable studies involved an aggregate of 561 rEpo and 529 placebo recipients. If rEpo was begun in the first week of life, the summary odds ratio (OR) for receiving any transfusion ("early" or "late") was 0.52, 95% confidence interval (CI): 0.34 to 0.79 (p=0.001). The OR for receiving an "early" transfusion was 0.54 (95% CI: 0.25 to 1.15; p=0.055), and the OR for receiving a "late" transfusion was 0.56 (95% CI: 0.37 to 0.83; p=0.036). Heterogeneity among studies was too great to estimate the effect of rEpo on the number of transfusions received or the volume of blood transfused (p<0.001 for the Q-test statistic). Subgroup analysis suggested that when rEpo is begun in the first week of life, neonates 1000 to 1500 g and >29 weeks are more likely to completely avoid transfusion than are extremely low-birth-weight (ELBW, <1000 g) neonates. No dose-response relationship was apparent between rEpo dose or iron dose and transfusion. No difference was apparent depending on whether the rEpo was given subcutaneously vs intravenously.

CONCLUSION

If rEpo is begun in the first week of life, a moderate reduction can be expected (p=0.001) in the proportion of VLBW neonates transfused. Reduction is less significant in "early" transfusion (p=0.055) than in "late" transfusion (p=0.036). Such treatment is not likely to eliminate transfusions among ELBW neonates completely.

Effects of vitamin E supplementation during erythropoietin treatment of the anaemia of prematurity

AIMS

To evaluate the effects of vitamin E supplementation on haemoglobin concentration and the requirement for transfusion in premature infants treated with erythropoietin and iron.

METHODS

Randomised, double blind, placebo controlled trial. Thirty infants </=32 weeks gestation and </=1250 g birth weight, who were defined as stable based on minimal requirements for respiratory support and phlebotomy, and absence of major congenital anomalies were enrolled. All were treated with erythropoietin and iron, and were randomised to receive, in addition, either vitamin E 50 IU/day or placebo for eight weeks or until discharge, whichever came first.

RESULTS

Despite higher vitamin E (alpha-tocopherol) levels in the experimental group in weeks 3 (49.0 v 28.1 micro mol/l) and 8 (66.2 v 38.5 micro mol/l), there were no differences in haemoglobin, reticulocyte count, iron concentration, or transfusion requirement.

CONCLUSIONS

Oral vitamin E supplementation at 50 IU/day does not increase the response of preterm infants to erythropoietin and iron. Vitamin E obtained through standard nutrition may have been sufficient or higher doses may be required.

[Recombinant human erythropoietin: analysis of a policy of treatment in an hospital based population of very-low-birthweight infants]

AIM OF THE STUDY

To evaluate a policy of treatment with human recombinant erythropoietin (rhEPO) and to describe factors related to red blood cell transfusions (RBCTs) in treated neonates.

STUDY

Prospective, observative study.

PATIENTS AND METHODS

One-hundred and sixty-five neonates with gestational age (GA) < 30 weeks and/or birthweight < 1000g admitted between may 1998 and october 1999. Ninety were excluded (congenital malformations n = 6, deaths n = 16, referral to a general hospital before discharge n = 67, ECMO n = 1). Data about the characteristics of the population, the severity of the neonatal period, hemoglobin at birth, blood loses, treatment with rhEPO, number of red blood cells transfusions (RBCTs) and donors were recorded in all infants.

RESULTS

Thirty-eight in seventy-five (51%) neonates received 112 blood transfusions. Eighty-eight were prescribed after day 15. In most of the cases (n = 68), RBCTs were done according to the protocol. In 20 cases (23%) infants were transfused during a late-onset infection. No difference was observed between the non-transfused (group I) and the transfused neonates (group II) with regards to the drug administration: first dose on day 3 +/- 2, number of injections (17 +/- 4 vs 18 +/- 1, ns). The start of oral supplementation with iron was late (12j +/- 8 vs 19j +/- 10, ns). Infants in group II had a lower birthweight (850 +/- 240 vs 1050 +/- 160 g, p < 0,01) for a similar GA (28 +/- 1SA vs 28 +/- 2SA, ns) in association with an increased number of small for date babies (p = 0.03). Antenatal steroïds administration (89 vs 74%, ns), administration of surfactant (59 vs 81%, ns) were similar in the two groups. The Clinical Risk Index for Babies was higher in group II: 5 +/- 3 vs 2 +/- 1 (p < 0,001) as was the duration of oxygen delivery (53 +/- 44 vs 14 +/- 20 days, p < 0,01) and postnatal administration of corticosteroïds ( 38% vs 3%, p < 0.01).

CONCLUSION

The quality of iron administration, RBCTs and the limitation of donors could be improved in our population. Transfusions among neonates born before 30 weeks and/or with a birthweight of less than 1000 g and treated with rhEPO are associated with intrauterine malnutrition and a worse clinical condition on admission. Early identification of at risk neonates could improve prevention of RBCTs and the efficacy of rhEPO administration to preterm infants.

Recombinant erythropoietin and blood transfusion in selected preterm infants

OBJECTIVES

To comprehensively identify preterm infants likely to require blood transfusion and to investigate the effectiveness of recombinant erythropoietin in this high risk subgroup.

DESIGN

Double blind randomised controlled trial.

SETTING

Neonatal Intensive Care Unit, Middlemore Hospital, Auckland, New Zealand.

PATIENTS

Preterm infants < 33 weeks gestation and < 1700 g birth weight meeting specific criteria indicating a high possibility of requiring blood transfusion.

INTERVENTIONS

Predictors of blood transfusion were determined by analysis of preterm infants admitted to a neonatal intensive care unit over a two year period. Using the criteria developed, high risk infants entered the study and received erythropoietin or sham treatment until 34 weeks completed gestation. The sample size was calculated to detect a reduction of one blood transfusion per infant (significance level 5%, power 80%).

RESULTS

The selection criteria had a positive predictive value for transfusion of 91% and a negative predictive value of 94%. Mean birth weights and gestational ages were similar in the two groups. Absolute reticulocyte counts and haemoglobin values were higher in the group receiving erythropoietin. There was no significant difference in the number of blood transfusions received in the treatment and control groups. However, comparing transfusions given to < 1000 g infants after 30 days of age, there were significantly fewer transfusions in the erythropoietin group (mean (SD) 0.5 (0.7) in those receiving erythropoietin and 1.6 (1.1) in the controls). No adverse effects were noted.

CONCLUSIONS

The selection criteria for the study were highly predictive of subsequent transfusion. In the group receiving erythropoietin, a reduction in transfusion requirements was apparent only in the < 1000 g birthweight group after 1 month of age.

Human recombinant erythropoietin in the prevention and treatment of anemia of prematurity

Human recombinant erythropoietin has been studied extensively as treatment for a variety of anemias. Since in vitro studies showed the primary etiology of the anemia of prematurity to be insufficient serum erythropoietin concentrations, clinical trials have evaluated the administration of human recombinant erythropoietin to preterm infants to treat this indication. These studies were followed by pharmacokinetic determinations in animal models and preterm infants, which revealed that preterm infants required greater doses of human recombinant erythropoietin because of a more rapid clearance and greater volume of distribution. Recent studies have focused on the administration of human recombinant erythropoietin in the first weeks of life to alleviate the anemia caused by excessive phlebotomy losses, and to prevent the anemia of prematurity. In addition, human recombinant erythropoietin has been tried clinically in a variety of neonatal populations in an attempt to decrease or eliminate transfusions. Although much information has been accumulated about the clinical use of human recombinant erythropoietin in preterm infants over the last 15 years, many questions remain unanswered. The evolution of clinical practice in the care of extremely low birthweight infants continues to affect the number of transfusions. It is likely that human recombinant erythropoietin administration in combination with instituting rigorous transfusion guidelines and decreasing phlebotomy losses will have the greatest impact in decreasing transfusion requirements in all preterm and term neonates, regardless of the etiology of their anemia.

Early treatment with erythropoietin beta ameliorates anemia and reduces transfusion requirements in infants with birth weights below 1000 g

OBJECTIVE

To investigate whether recombinant erythropoietin (rhEPO) reduces the need for transfusion in extremely low birth weight (ELBW) infants (birth weight 500-999 g) and to determine the optimal time for treatment.

METHODS

In a blinded multicenter trial, 219 ELBW infants were randomized on day 3 to one of 3 groups: early rhEPO group (rhEPO from the first week for 9 weeks, n = 74), late rhEPO group (rhEPO from the fourth week for 6 weeks, n = 74), or control group (no rhEPO, n = 71). All infants received enteral iron (3-9 mg/kg/day) from the first week. The rhEPO beta dose was 750 IU/kg/week. Success was defined as no transfusion and hematocrit levels never below 30%.

RESULTS

Success rate was 13% in the early rhEPO group, 11% in the late rhEPO group, and 4% in the control group (P =.026 for early rhEPO versus control group). Median transfusion volume was 0.4 versus 0.5 versus 0.7 mL/kg/day (P =.02) and median donor exposure was 1.0 versus 1.0 versus 2.0 (P =.05) in the early rhEPO group, the late rhEPO group, and the control group, respectively. Infection risk was not increased and weight gain was not delayed with rhEPO beta.

CONCLUSION

Early rhEPO beta treatment effectively reduces the need for transfusion in ELBW infants.

Iron status and the treatment of the anemia of prematurity

Many unanswered issues regarding rhEPO therapy in prematurity remain, including which premature infants best respond to rhEPO, what the long-term effect of decreased erythrocyte transfusions is, how nutritional supplementation optimizes the effect of rhEPO, whether or not rhEpo therapy causes iron deficiency later in life, and whether or not it is safe to supplement with parenteral iron. Further study of rhEPO therapy and iron status in prematurity is necessary.

Nutrient requirements for preterm infant formulas

Achieving appropriate growth and nutrient accretion of preterm and low birth weight (LBW) infants is often difficult during hospitalization because of metabolic and gastrointestinal immaturity and other complicating medical conditions. Advances in the care of preterm-LBW infants, including improved nutrition, have reduced mortality rates for these infants from 9.6 to 6.2% from 1983 to 1997. The Food and Drug Administration (FDA) has responsibility for ensuring the safety and nutritional quality of infant formulas based on current scientific knowledge. Consequently, under FDA contract, an ad hoc Expert Panel was convened by the Life Sciences Research Office of the American Society for Nutritional Sciences to make recommendations for the nutrient content of formulas for preterm-LBW infants based on current scientific knowledge and expert opinion. Recommendations were developed from different criteria than that used for recommendations for term infant formula. To ensure nutrient adequacy, the Panel considered intrauterine accretion rate, organ development, factorial estimates of requirements, nutrient interactions and supplemental feeding studies. Consideration was also given to long-term developmental outcome. Some recommendations were based on current use in domestic preterm formula. Included were recommendations for nutrients not required in formula for term infants such as lactose and arginine. Recommendations, examples, and sample calculations were based on a 1000 g preterm infant consuming 120 kcal/kg and 150 mL/d of an 810 kcal/L formula. A summary of recommendations for energy and 45 nutrient components of enteral formulas for preterm-LBW infants are presented. Recommendations for five nutrient:nutrient ratios are also presented. In addition, critical areas for future research on the nutritional requirements specific for preterm-LBW infants are identified.

Anaemia of prematurity: treatment with erythropoietin

Anemia of prematurity is a hyporegenerative anemia usually appearing after the second week, reaching highest intensity in the second month of life. It's normocytic and normochromic with low reticulocyte count. It has been attributed to EPO deficiency. The low EPO levels detected in premature infants and the proper response to synthetic erythropoietin suggested that EPO administration in premature of < or =32 weeks gestational age could be of benefit trying to maintain or increase the hematocrit levels. Protocols of EPO administration to premature babies should always be considered as EPO+Fe, keeping ferritin levels over 100 ng/ml. Failures to EPO+Fe treatment in very small premature babies, measured as no decrease in the need of blood transfusions, may be due to the amount of blood looses that should be restricted.

Neonatal iron nutrition

Preterm infants are prone to iron deficiency. Their total body iron content at birth is low and gets further depleted by clinical practices such as uncompensated phlebotomy losses and exogenous erythropoietin administration during the neonatal period. Early iron deficiency appears to adversely affect cognitive development in human infants. To maintain iron sufficiency and meet the iron demands of catch-up postnatal growth, iron supplementation is prudent in preterm infants. A dose of 2-4 mg/kg/day is recommended for preterm infants who are fed exclusively human milk. A dose of 6 mg/kg/day or more is needed with the use of exogenous erythropoietin or to correct preexisting iron deficiency. However, due to the poor antioxidant capabilities of preterm infants and the potential role of iron in several oxidant-related perinatal disorders, indiscriminate iron supplementation should be avoided.

Meta-analysis of controlled clinical trials studying the efficacy of rHuEPO in reducing blood transfusions in the anemia of prematurity

BACKGROUND

Recombinant human EPO (rHuEPO) has not gained broad acceptance in the treatment of the anemia of prematurity, because its efficacy in diminishing RBC transfusions is questionable. Meta-analysis was used to investigate the extent and reasons for variation in the results of published clinical trials.

STUDY DESIGN AND METHODS

Prospective controlled trials published from 1990 through 1999 were retrieved; 21 met the criteria for meta-analysis. Calculated across these studies were the summary OR of RBC transfusion in treated neonates as compared with controls and the summary mean difference between controls and treated neonates in the volume of RBCs transfused and the number of RBC transfusions per infant. Twelve study descriptors were examined as possible reasons for the variation in results.

RESULTS

Results of 21 eligible studies varied widely (p<0.001 for the Q test statistic), and this variation persisted in most analyses when studies were stratified by individual study descriptors. When the difference in volume of RBCs transfused was the outcome measure, variation was modest across the four studies with highly desired characteristics (i.e., high blindness and design quality scores, "conservative" transfusion criteria, and the majority of neonates weighing <1 kg at birth), and treatment with rHuEPO reduced RBC transfusions by an average of 11.0 mL per kg (p<0.001).

CONCLUSION

Benefit from rHuEPO is detected across high-quality studies using conservative RBC transfusion criteria. However, there is extreme variation overall in the findings of available trials, and-until this variation is accounted for-it is premature to recommend rHuEPO as standard treatment for the anemia of prematurity.

Red blood cell transfusions in very and extremely low birthweight infants under restrictive transfusion guidelines: is exogenous erythropoietin necessary?

OBJECTIVE

To examine the number and volume of red blood cell transfusions (RBCTs) in very and extremely low birthweight infants under restrictive red blood cell transfusion guidelines without erythropoietin administration, and to compare the results with those reported in similar infants receiving erythropoietin.

METHODS

From April 1996 to June 1999, all RBCTs given to infants with a birth weight of less than 1500 g were prospectively recorded. Data on RBCT combined with erythropoietin treatment and RBCT guidelines were extracted from four prospective randomised trials of erythropoietin for anaemia of prematurity.

RESULTS

When the restrictive RBCT guidelines were followed, the number of RBCTs and volume transfused were similar to those reported during erythropoietin administration.

CONCLUSIONS

RBCT guidelines may have a similar impact on RBCT in very low birthweight infants to the administration of erythropoietin. The effect of RBCT guidelines on RBCT frequency should be considered when evaluating the efficacy of erythropoietin administration to preterm infants.