Early red cell transfusion is associated with development of severe retinopathy of prematurity

Storage properties of platelet concentrates from umbilical cord blood prepared using three different methods

BACKGROUND

Thrombocytopenia, common in preterm newborns, may increase bleeding risk and is often treated with transfusions. Recent studies reveal that transfusing platelets at a high threshold worsens outcomes, possibly due to a "developmental mismatch" between adult-derived platelets and neonatal hemostatic system. Cord blood-derived platelet concentrates (CBPCs) could be an alternative for newborns. Our study aims to produce and evaluate the quality parameters of CBPCs during storage.

STUDY DESIGN AND METHODS

Cord blood was collected from placentas after near-term and full-term pregnancies. Several production methods were attempted to obtain CBPCs, varying centrifugation settings, filtration, and dilution procedures. Adult-derived platelet concentrates (PCs) processed with the same methods, and standard PCs from five buffy-coats were used as controls. Storage tests were performed on days 2, 4-5, 7 from the collection.

RESULTS

CBPCs parameters were compared with adult-derived PCs, and no significant differences were found for mean platelet volume (MPV), swirling, morphology, glucose, lactate, pCO2, and pO2. pH and bicarbonate were lower in CBPCs. Some significant differences between methods in CD62P expression and JC-1 ratio were observed. Compared with standard PCs, CBPCs showed lower platelet concentration, pH, and JC-1. Additionally, both in CBPCs as well as in control PCs, the apoptosis marker phosphatidylserine was elevated.

DISCUSSION

CBPCs were of comparable quality to control PCs during storage. However, apoptosis markers in both groups were elevated, suggesting processing and storage of low volumes of PCs require further optimization. Also, filtration of low volumes leads to significant platelet loss, an issue that requires remedy.

Red Blood Cell Transfusion for Incidence of Retinopathy of Prematurity: Prospective Multicenter Cohort Study

Background

Retinopathy of prematurity (ROP) is a leading cause of visual impairment and blindness in preterm infants.

Objective

This study sought to investigate the association between red blood cell (RBC) transfusion and ROP in very preterm infants (VPIs) to inform clinical strategies for ROP prevention and treatment.

Methods

We designed a prospective multicenter cohort study that included VPIs and follow-up data from January 2017 to December 2022 at 3 neonatal clinical medicine centers. They were categorized into a transfusion group (infants who received an RBC transfusion within 4 wk) and a nontransfusion group. The relationship between RBC transfusion and ROP incidence was assessed using binary logistic regression, with subgroup analyses based on gestational age, birth weight, sex, and sepsis status. Inverse probability of treatment weighting and propensity score matching were applied to account for all potential confounding factors that could affect ROP development, followed by sensitivity analysis.

Results

The study included 832 VPIs, including 327 in the nontransfusion group and 505 in the transfusion group. The transfusion group had a lower average birth weight and gestational age and a greater incidence of ROP, ≥stage 2 ROP, and severe ROP. Logistic regression analysis revealed that the transfusion group had a significantly greater risk of ROP (adjusted odds ratio [aOR] 1.70, 95% CI 1.14-2.53, P=.009) and ≥stage 2 ROP (aOR 1.68, 95% CI 1.02-2.78, P=.04) but not severe ROP (aOR 1.75, 95% CI 0.61-5.02, P=.30). The trend analysis also revealed an increased risk of ROP with an increasing number of transfusions and a larger volume of blood transfused (P for trend<.001). Subgroup analyses confirmed a consistent trend, with the transfusion group at a higher risk for ROP across all subgroups. Inverse probability of treatment weighting and propensity score matching analyses supported the initial findings.

Conclusions

For VPIs, RBC transfusion significantly increases the risk of ROP, and the risk increases with an increasing number of transfusions and volume of blood transfused.

Estimation of gestational age-specific reference intervals for coagulation assays in a neonatal intensive care unit using real-world data

BACKGROUND

Interpretation of coagulation testing in neonates currently relies on reference intervals (RIs) defined from older patient cohorts. Direct RI studies are difficult, but indirect estimation may allow us to infer normative neonatal distributions from routinely collected clinical data.

OBJECTIVE

Assess the utility of indirect reference interval methods in estimating coagulation reference intervals in critically ill neonates.

METHODS

We analyzed first-in-life coagulation testing results from all patients admitted to a level IV neonatal intensive care unit between January 1, 2018, and January 1, 2024. Results obtained after transfusion of any blood product were excluded. Indirect RIs were estimated across gestational age groups using refineR and compared with currently reported intervals for patients less than 1 year of age.

RESULTS

Prothrombin times (PTs) and international normalized ratios (INRs) were available for 1128 neonates, while activated partial thromboplastin times (APTTs) were available for 790 neonates. The indirect RI was 10 to 25 seconds in preterm, 10 to 22 seconds in term, and 10 to 24 seconds in all neonates for PT; 0.7 to 2.1 in preterm, 0.8 to 1.8 in term, and 0.8 to 1.9 in all neonates for INR; and 25 to 68 seconds in preterm, 25 to 58 seconds in term, and 25 to 62 seconds in all neonates for APTT. Compared with our current intervals, the indirect RIs would flag 58% fewer PT, 43% fewer INR, and 17% fewer APTT results as abnormal.

CONCLUSION

Indirectly estimated RIs in neonates admitted to intensive care show substantial divergence from current, first-year-of-life RIs, leading to an abundance of abnormal flags. The associations between these flags and provider behavior, transfusion practice, or clinical outcomes are areas of future exploration.

Why might cord blood be a better source of platelets for transfusion to neonates?

Thrombocytopenia (defined as a platelet count <150×109/L) is a common condition in preterm neonates and may occur in 18-35% of all infants admitted to the Neonatal Intensive Care Unit (NICU). Neonatal platelet functionality in terms of reactivity is often described as reduced compared to adults, even in healthy, term neonates. However, this platelet "hyporeactivity" does not correspond to a global functional impairment of the normal delicately balanced neonatal hemostatic system. The extent to which neonatal thrombocytopenia and platelet hyporeactivity contribute to the bleeding risk in preterm neonates remains unknown. Prophylactic platelet transfusions are often administered to them to reduce the risk of bleeding. However, recent literature indicates that adopting a higher platelet transfusion threshold than a lower one results in significantly higher death rates or major bleeding and can be harmful. Although the mechanism by which this occurs is not entirely clear, a mismatch between adult transfused platelets and the neonatal hemostatic system, as well as volume overload, are speculated to be potentially involved. Therefore, future research should consider novel transfusion products that may be more suitable for premature neonates. Blood products derived from umbilical cord blood (UCB) are promising, as they might perfectly match neonatal blood features. Here, we discuss the current knowledge about UCB-derived products, focusing on UCB-derived platelet concentrates and their potential for future clinical application. We will discuss how they may overcome the potential risks of transfusing adult-derived platelets to premature infants while maintaining efficacy.

Neonatal Sepsis Episodes and Retinopathy of Prematurity in Very Preterm Infants

Importance

Retinopathy of prematurity (ROP) is a major morbidity of preterm infants causing visual impairment, including blindness, for which timely treatment is vital and prevention is key. Increasing evidence suggests that exposure to neonatal sepsis contributes to ROP development.

Objective

To investigate the association between neonatal sepsis and ROP in 2 large-scale cohorts of preterm infants born at less than 29 weeks' gestation.

Design, Setting, and Participants

This retrospective cohort study was conducted using data from the German Neonatal Network (GNN) and Norwegian Neonatal Network (NNN). The GNN involves 68 and the NNN includes 21 level III neonatal intensive care units. Participants were infants born at a gestation of 22 weeks and 0 days to 28 weeks and 6 days and enrolled in the GNN between January 1, 2009, and December 31, 2022, and NNN between January 1, 2009, and December 31, 2018. Data were analyzed from February through September 2023.

Exposure

Single or multiple episodes of culture-proven sepsis.

Main Outcomes and Measures

Any ROP and treatment-warranted ROP.

Results

Among 12 794 infants in the GNN (6043 female [47.2%] and 6751 male [52.8%]; mean [SD] gestational age, 26.4 [1.5] weeks) and 1844 infants in the NNN (866 female [47.0%] and 978 male [53.0%]; mean [SD] gestational age, 25.6 [1.5] weeks), the mean (SD) birth weight was 848 (229) g and 807 (215) g, respectively. Any ROP was present in 6370 infants (49.8%) in GNN and 620 infants (33.6%) in NNN, and treatment-warranted ROP was present in 840 infants (6.6%) in GNN and 140 infants (7.6%) in NNN. In both cohorts, there were increasing rates of treatment-warranted ROP with each sepsis episode (no sepsis: 572 of 10 658 infants [5.4%] in GNN and 85 of 1492 infants (5.7%) in NNN; 1 episode: 190 of 1738 infants in GNN [10.9%] and 29 of 293 infants [9.9%] in NNN; 2 episodes: 53 of 314 infants in GNN [16.9%] and 13 of 49 infants [26.5%] in NNN; 3 episodes: 25 of 84 infants [29.8%] in GNN and 3 of 10 infants [30.0%] in NNN). After adjusting for multiple confounders in the GNN dataset, the number of sepsis episodes was associated with ROP and treatment-warranted ROP compared with 0 episodes (1 episode: adjusted odds ratio [aOR], 1.44 [95% CI, 1.27-1.63]; P < .001 and OR, 1.60 [95% CI, 1.31-1.96]; P < .001, respectively; 2 episodes: OR, 1.81 [95% CI, 1.35-2.42]; P < .001 and OR, 2.38 [95% CI, 1.68-3.37]; P < .001, respectively; 3 episodes: OR, 4.39 [95% CI, 2.19-8.78]; P < .001 and OR, 3.88 [95% CI, 2.29-6.55]; P < .001, respectively). These associations were confirmed for any ROP by propensity score matching (for example, the aOR with propensity score matching was 1.76 [95% CI, 1.54-2.02]; P < .001 for 1 episode vs 0 episodes and 1.58 [95% CI, 1.12-2.22]; P = .007 for 3 episodes vs 0 or 1 episode). In the NNN dataset, surgical NEC was associated with treatment-warranted ROP (multivariable analysis: aOR, 3.37 [95% CI, 1.78-6.37]; P < .001).

Conclusions and Relevance

This study found that in the large-scale GNN cohort, recurrent culture-proven sepsis was associated with ROP and treatment-warranted ROP in infants born at less than 29 weeks.

Effect of Minimization of Early Blood Sampling Losses Among Extremely Premature Neonates: A Randomized Clinical Trial

OBJECTIVE

To evaluate the effect of blood sampling stewardship on transfusion requirements among infants born extremely preterm.

STUDY DESIGN

In this single-center, randomized controlled trial (RCT), infants born at <28 weeks of gestation and birth weight of <1000 g were randomized at 24 hours of age to two different blood sampling approaches: restricted sampling (RS) vs conventional sampling (CS). The stewardship intervention in the RS group included targeted reduction in blood sampling volume and frequency and point of care testing methods in the first 6 weeks after birth. Both groups received early recombinant erythropoietin from day three of age. Primary outcome was the rate of early red blood cell (RBC) transfusions in the first six postnatal weeks.

RESULTS

A total of 102 infants (mean gestational age: 26 weeks; birth weight: 756 g) were enrolled. Fidelity to the sampling protocol was achieved in 95% of the infants. Sampling losses in the first 6 weeks were significantly lower in the RS group (16.8 ml/kg vs 23.6 ml/kg, P < .001). The RS group had a significantly lower rate of early postnatal RBC transfusions (41% vs 73%, RR: 0.56 [0.39-0.81], P = .001). The hazard of needing a transfusion during neonatal intensive care unit (NICU) stay was reduced by 55% by RS. Mortality and neonatal morbidities were similar between the two groups.

CONCLUSION

Minimization of blood sampling losses by approximately one-third in the first 6 weeks after birth leads to substantial reduction in the early red blood cell transfusion rate in infants born extremely preterm and weighing <1000 g at birth.

TRIAL REGISTRATION

http://www.ctri.nic.in (CTRI/2020/01/022  964).

Profile and risk factors of sight-threatening retinopathy of prematurity: Experience from SNCU in North India

BACKGROUND

This research aimed to identify the clinical profile and risk factors of retinopathy of prematurity (ROP) among "at-risk" newborns treated at a sick newborn care unit (SNCU) located at high altitude in North India, with the intention of contributing to formulate regional and national ROP screening guidelines.

MATERIALS AND METHODS

In a prospective observational study from 2021 to 2022, outborn and inborn babies eligible for ROP screening were screened.

RESULTS

Total 39/122 screened neonates had laser for Type 1 ROP, and 22/39 (56.4%) had aggressive ROP (AROP). The average birth weight (BW) was 1803.87 g, and the average gestational age was 34 weeks. Respiratory distress, bronchopulmonary dysplasia, sepsis, and apnea were present in 57.3%, 13%, 52.5%, and 25.4%, respectively. Sight-threatening ROP was present in 50% below 28+6 weeks, 27% between 29 and 30+6 weeks, 52% between 31 and 33+6 weeks, and 15% with gestation >34 weeks. Two babies with Type 1 ROP weighed >2 kg and one had AROP. Upon regression analysis, BW <1500 g, gestation <32 weeks, oxygen >48 h, clinical sepsis, total SNCU stay >14 days, continuous positive airway pressure support with oxygen >50%, and >10 days to achieve full feeds were associated with severe ROP. Caffeine to treat apnea and kangaroo mother care reduced ROP. None had short-term unfavorable outcome.

CONCLUSION

With similar infrastructure and work force shortage in most SNCUs, these findings can be generalized. The burden of Type 1 and AROP is increasing, as seen in higher gestation and BWs. This needs revision of ROP screening criteria at local and national level. It is crucial to emphasize on the importance of pediatrician and ophthalmologist collaboration, early ROP screening, diagnosis, and treatment to stop disease progression to severe ROP.

Histological Chorioamnionitis and Funisitis as New Risk Factors for Retinopathy of Prematurity: A Meta-analysis

OBJECTIVE

 The role of placental inflammation in neonatal morbidities is underestimated due to lack of placental examination. This meta-analysis aims to assess the association between histological chorioamnionitis (HCA) with and without funisitis (FUN) and risk of retinopathy of prematurity (ROP).

STUDY DESIGN

 Forty-five studies reporting (unadjusted) data on HCA without FUN and HCA with FUN in neonates with ROP were included. Primary outcomes were any stage ROP and severe ROP. Potential confounders explored were gestational age (GA) at birth, birthweight, maternal steroid use, necrotizing enterocolitis, sepsis (suspected/proven) and mechanical ventilation duration.

RESULTS

 Neonates with HCA had increased risk for any stage ROP (odds ratio [OR] 1.8; 95% confidence interval [CI] 1.3-2.4) and severe ROP (OR 1.5; 95% CI 1.2-1.8) compared with neonates without HCA. The rates of any stage ROP (OR 1.8; 95% CI 1.4-2.2) and severe ROP (OR 1.4; 95% CI 1.1-1.6) were higher in neonates with FUN compared with neonates without FUN. Multivariate meta-regression analysis suggests that lower GA increases the effect size between FUN and severe ROP.

CONCLUSION

 This meta-analysis confirms that presence of HCA and FUN are risk factors for any stage ROP and severe ROP. Structured histological placental examination of HCA and FUN may be a tool to further refine the ROP risk profile.

KEY POINTS

· This systematic review confirms that HCA is a risk factor for ROP.. · This meta-analysis reveals that FUN results in an even higher risk for developing ROP.. · Placental examination of HCA/FUN may be a tool to further refine the ROP risk profile..

Retrospective cohort study of neonatal blood transfusion in China

BACKGROUND

Blood transfusion therapy is extremely important for certain neonatal diseases, but the threshold for neonatal blood transfusion is not the same in different countries. Until now, clinical studies to determine the suitable threshold for newborns in China are lacking. Therefore, it is of high importance to establish a multi-center cohort study to explore appropriate transfusion thresholds for newborns in China.

METHODS

This retrospective cohort study investigated neonatal blood transfusion therapy administered from January 1, 2017 to June 30, 2018, with the aim of evaluating the effect of restricted and nonrestricted blood transfusion on neonatal health. The subjects were enrolled in 46 hospitals in China. A total of 5669 neonatal cases were included in the study. Clinical diagnosis and transfusion treatment of these neonates were collected and the data were retrospectively analyzed. The neonates were followed up 1 week and 1 month after leaving the hospital. The newborns' and their mothers' data were collected containing 280 variables in the database. The primary outcome of the study was mortality, and the secondary outcomes were complications, hospital stays, NICU hospital stays and hospital costs.

RESULTS

Results from the < 1500 g group showed that there was a higher mortality rate in the restricted transfusion group (11.41%) when compared with the non-restricted transfusion group (5.12%) (P = 0.000). Among the secondary outcomes, the restricted transfusion group had fewer costs. Results from the 1500-2500 g group showed that the mortality rates of the restricted and non-restricted transfusion groups were 3.53% and 4.71%, respectively, however there was no statistical significance between the two groups (P = 0.345). Among the secondary outcomes, the restricted transfusion group had fewer hospital stays, NICU hospital stays and hospital costs. The incidence of necrotizing enterocolitis was lower in the restricted transfusion group (OR, 2.626; 95% confidence interval [CI], 1.445 to 4.773; P = 0.003). The results from the ≥ 2500 g restricted transfusion group suggested that the mortality rate of (3.02%) was significantly lower than that of non-restricted transfusion group (9.55%) (P = 0.000). Among the secondary outcomes, the restricted transfusion group had fewer hospital stays and hospital costs. The incidence of retinopathy of prematurity was lower in the restricted transfusion group (OR, 4.624; 95% confidence interval [CI], 2.32 to 9.216; P = 0.000).

CONCLUSIONS

Current transfusion protocols for newborns weighing less than 1500 g may be inappropriate and lead to higher mortality. The current transfusion threshold performed better for the other two weight groups.

Blood Donor Sex and Outcomes in Transfused Infants

Red blood cell transfusion is common in neonatal intensive care. Multiple trials have evaluated different thresholds for when to administer red blood cell transfusion. In contrast, there has been less focus on studies of the characteristics of red blood cells transfused into neonates. In this review, the authors summarize the emerging literature on the potential impact of the sex of blood donors on outcomes in transfused neonates using a systematic search strategy. The authors review the uncertainty generated from studies with conflicting findings and discuss considerations regarding the impact of blood donor sex and other characteristics on neonatal outcomes.

Allogenic Cord Blood Transfusion in Preterm Infants

Repeated red blood cell (RBC) transfusions in preterm neonates cause the progressive displacement of fetal hemoglobin (HbF) by adult hemoglobin. The ensuing increase of oxygen delivery may result at the cellular level in a dangerous condition of hyperoxia, explaining the association between low-HbF levels and retinopathy of prematurity or bronchopulmonary dysplasia. Transfusing preterm neonates with RBC concentrates obtained from allogeneic umbilical blood is a strategy to increase hemoglobin concentration without depleting the physiologic HbF reservoir. This review summarizes the mechanisms underlying a plausible beneficial impact of this strategy and reports clinical experience gathered so far in this field.

Analysis of trends in retinopathy of prematurity over 5 years in a tertiary neonatal intensive care unit

AIM

The aim of the study was to look at the incidence and trend of retinopathy of prematurity (ROP) between 2017 and 2021 in a tertiary neonatal intensive care unit (NICU) in Australia and to compare potential modifiable risk factors of ROP between preterm infants who required treatment for ROP and who did not need treatment.

METHODS

This retrospective study used the data of newborn infants who were <31 weeks gestational age (GA) or birth weight (BW) of <1250 g born between 2017 and 2021 at a tertiary NICU in Australia (n = 261). Univariate analysis using t test for continuous data, Fischer exact test for categorical data and multiple logistic regression analysis were undertaken to identify any significant differences between two groups.

RESULTS

A total number of 261 infants were studied. 55.9% of infants developed any type of ROP (146 infants out of 261 infants), type 1 ROP was 5.4% (14 out of 261) and aggressive ROP (AROP) was 3% (8 out of 261). Out of 146 infants who were diagnosed with ROP, 22 (15%) of them required treatment. Mean GA for those who underwent ROP treatment was 25.6 (±1.47) weeks and for those who did not require treatment was 27.6 (±1.95) weeks. The mean BWs for those who needed treatment was 764 (±189.32) g and for those who did not need treatment was 1039 (±306.06) g. The mean duration of invasive ventilation for infants with ROP requiring treatment and those who did not require treatment were 23.95 (±22.41) days and 9.89 (±17.2) days. The total duration of oxygen requirement was 235.54 (±160.5) days and 121.11 (±117.34) days for those who needed treatment and those who did not need treatment respectively. Among infants who required treatment for ROP, 68.18% required blood transfusion whereas among those who did not need treatment, 24.19% required blood transfusion.

CONCLUSION

Lower GA, lower BW, longer duration of invasive ventilation, longer total duration of oxygen requirement and blood transfusion in first 2 weeks of life were significant in preterm infants who required treatment for ROP compared with those who did not.

Therapeutic potential of iron chelators in retinal vascular diseases

Iron is one of the necessary metal elements in the human body. There are numerous factors that control the balance of iron metabolism, and its storage and transportation mechanisms are intricate. As one of the most energy-intensive tissues in the body, the retina is susceptible to iron imbalance. The occurrence of iron overload in the retina leads to the generation of a significant quantity of reactive oxygen species. This will aggravate local oxidative stress and inflammatory reactions and even lead to ferroptosis, eventually resulting in retinal dysfunction. The blood-retina-retinal barrier is eventually harmed by oxidative stress and elevated inflammation, which are characteristics of retinal vascular disorders. The pathophysiology of retinal vascular disorders may be significantly influenced by iron. Recently, iron-chelating agents have been found to have antioxidative and anti-inflammatory actions in addition to iron chelating. Therefore, iron neutralization is considered to be a new and potentially useful therapeutic strategy. This article reviews the iron overload in retinal vascular diseases and discusses the therapeutic potential of iron-chelating agents.

Reticulocyte Count: The Forgotten Factor in Transfusion Decisions for Extremely Low Birth Weight Infants

OBJECTIVE

Extremely low birth weight (ELBW) infants often receive transfusions of packed red blood cells (PRBCs). Long-term outcomes of infants treated with liberal versus restricted transfusion criteria have been evaluated with conflicting results. Clinicians incorporate a reticulocyte count (RC) in their transfusion decisions. There is a lack of information on reference ranges for RCs in growing ELBW infants and whether infant's chronologic age or corrected gestational age (GA) generates a specific trend in the RCs. Our aim was to evaluate the levels of RCs obtained from ELBW infants over the course of the initial hospitalization.

STUDY DESIGN

A retrospective chart review of ELBW infants treated in the neonatal intensive care unit (NICU) and had RCs performed. We analyzed the RCs to observe trends based on the chronologic age and corrected GA.

RESULTS

A total of 738 RCs were analyzed. A positive trend in RCs that reached a peak at 32 to 34 weeks' corrected GA and then experienced a downward trend was observed.

CONCLUSION

Our report examines a very common hematologic test that is theoretically helpful but is in need of guidelines concerning the appropriate frequency of testing and its utility in making transfusion decisions in ELBW infants.

KEY POINTS

· RCs should help in making transfusion decisions for ELBW infants.. · No current reference ranges for RC in this population.. · No current reference ranges for RC based on GA and postnatal age..

Impact of level of neonatal care on phlebotomy and blood transfusion in extremely low birthweight infants: a prospective, multicenter, observational study

Objectives

To explore the level of neonatal care on cumulative phlebotomy loss (cPL) and red cell transfusions in extremely low birthweight [ELBW; birthweight (BW) <1,000 g] infants, up to 40 weeks post-conceptual age (PCA). The secondary objective was to determine the associations between cPL and number of transfusions and between transfusions and hospital outcomes.

Methods

A prospective, comparative, observational study was conducted in two level IV and two level III neonatal intensive care units (NICUs) in Thailand. Daily cPL volume and number of blood tests were recorded. Descriptive data are reported as frequency and percentage for categorical variables and median [25th percentile (P25), 75th percentile (P75)] for continuous data according to the data distribution. A p-value <0.05 was considered statistically significant.

Results

210 ELBW infants were included; 99 and 111 were admitted to level IV and level III NICUs, respectively. Birth weight of level IV infants was lower 780.0 [660.0, 875.0] vs. 865.0 [723.0, 930.0] g; p < 0.001]. Initial group hematocrits were similar (43.1% vs. 44.0%, p = 0.47). cPL for each infant was 28.1 [16.5, 46.4] ml. Level IV infants had more tests (n = 89 [54, 195] vs. 59 [37, 88], p < 0.001). Counterintuitively, there was a lower cPL trend in level IV infants, but this was insignificant (19.6 [12.3, 52.3] vs. 28.9 [19.3, 45.3] ml; p = 0.06). The number of transfusions in both NICUs was similar 4 [2, 6], with a strong correlation between cPL and number of transfusions (r = 0.79, p < 0.001). Transfusions were significantly associated with bronchopulmonary dysplasia [BPD; adjusted RR (95% CI): 2.6 (1.2, 5.3), p = 0.01].

Conclusions

Level IV NICUs conducted more blood tests in ELBW infants without a difference in cPL, and number of transfusions. Cumulative PL correlated with number of transfusions and was associated with BPD risk. Minimizing cPL by point-of-care tests and restrictive transfusion criteria, may reduce need for transfusion.

Genetic Modulation of the Erythrocyte Phenotype Associated with Retinopathy of Prematurity-A Multicenter Portuguese Cohort Study

The development of retinopathy of prematurity (ROP) may be influenced by anemia or a low fetal/adult hemoglobin ratio. We aimed to analyze the association between DNA methyltransferase 3 β (DNMT3B) (rs2424913), methylenetetrahydrofolate reductase (MTHFR) (rs1801133), and lysine-specific histone demethylase 1A (KDM1A) (rs7548692) polymorphisms, erythrocyte parameters during the first week of life, and ROP. In total, 396 infants (gestational age < 32 weeks or birth weight < 1500 g) were evaluated clinically and hematologically. Genotyping was performed using a MicroChip DNA on a platform employing iPlex MassARRAY^®. Multivariate regression was performed after determining risk factors for ROP using univariate regression. In the group of infants who developed ROP red blood cell distribution width (RDW), erythroblasts, and mean corpuscular volume (MCV) were higher, while mean hemoglobin and mean corpuscular hemoglobin concentration (MCHC) were lower; higher RDW was associated with KDM1A (AA), MTHFR (CC and CC + TT), KDM1A (AA) + MTHFR (CC), and KDM1A (AA) + DNMT3B (allele C); KDM1A (AA) + MTHFR (CC) were associated with higher RDW, erythroblasts, MCV, and mean corpuscular hemoglobin (MCH); higher MCV and MCH were also associated with KDM1A (AA) + MTHFR (CC) + DNMT3B (allele C). We concluded that the polymorphisms studied may influence susceptibility to ROP by modulating erythropoiesis and gene expression of the fetal/adult hemoglobin ratio.

Effect of Early Erythropoietin on Retinopathy of Prematurity: A Stratified Meta-Analysis

BACKGROUND

Recombinant human erythropoietin (rhEPO) lost its role in minimizing red blood cell transfusion in very preterm infants after it had been associated with severe retinopathy of prematurity (ROP). Previous systematic reviews did not stratify ROP by gestation and birth weight (BW).

OBJECTIVES

The aim of this study was to investigate the effect of early prophylactic rhEPO on ROP in a stratified meta-analysis of randomized controlled trials (RCTs).

METHODS

The databases EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials were searched in January 2022 and complemented by citation searching. RCTs comparing early rhEPO treatment with no treatment or placebo were selected if they were published in a peer-reviewed journal and reported ROP outcomes. Previously unpublished data were requested from the study authors to allow stratified analyses by gestational age (GA) and BW. Data were extracted and analyzed using the standard methods of the Cochrane Neonatal Review Group. Pre-specified outcomes were "ROP stage ≥3" (primary outcome) and "any ROP."

RESULTS

Fourteen RCTs, comprising 2,040 infants of <29 weeks of GA, were included for meta-analysis. Data syntheses showed no effects of rhEPO on ROP stage ≥3 or on any ROP, neither in infants of <29 weeks GA, nor in infants of <1,000 g BW, nor in any GA strata. The risk ratio (95% confidence interval) for ROP stage ≥3 in infants of <29 weeks of GA was 1.13 (0.84, 1.53), p = 0.41 (quality of evidence: moderate).

CONCLUSIONS

The present meta-analysis detected no effects of early rhEPO on ROP in any comparison, but most stratified analyses were limited by low statistical power.

Modifiable Risk Factors and Preventative Strategies for Severe Retinopathy of Prematurity

Severe ROP is characterized by the development of retinal fibrovascular proliferation that may progress to retinal detachment. The purpose of this report is to review five of the most common and well-studied perinatal and neonatal modifiable risk factors for the development of severe ROP. Hyperoxemia, hypoxia, and associated prolonged respiratory support are linked to the development of severe ROP. While there is a well-established association between clinical maternal chorioamnionitis and severe ROP, there is greater variability between histologic chorioamnionitis and severe ROP. Neonatal sepsis, including both bacterial and fungal subtypes, are independent predictors of severe ROP in preterm infants. Although there is limited evidence related to platelet transfusions, the risk of severe ROP increases with the number and volume of red blood cell transfusions. Poor postnatal weight gain within the first six weeks of life is also strongly tied to the development of severe ROP. We also discuss preventative strategies that may reduce the risk of severe ROP. Limited evidence-based studies exist regarding the protective effects of caffeine, human milk, and vitamins A and E.

Systemic Cytokines in Retinopathy of Prematurity

Retinopathy of prematurity (ROP), a vasoproliferative vitreoretinal disorder, is the leading cause of childhood blindness worldwide. Although angiogenic pathways have been the main focus, cytokine-mediated inflammation is also involved in ROP etiology. Herein, we illustrate the characteristics and actions of all cytokines involved in ROP pathogenesis. The two-phase (vaso-obliteration followed by vasoproliferation) theory outlines the evaluation of cytokines in a time-dependent manner. Levels of cytokines may even differ between the blood and the vitreous. Data from animal models of oxygen-induced retinopathy are also valuable. Although conventional cryotherapy and laser photocoagulation are well established and anti-vascular endothelial growth factor agents are available, less destructive novel therapeutics that can precisely target the signaling pathways are required. Linking the cytokines involved in ROP to other maternal and neonatal diseases and conditions provides insights into the management of ROP. Suppressing disordered retinal angiogenesis via the modulation of hypoxia-inducible factor, supplementation of insulin-like growth factor (IGF)-1/IGF-binding protein 3 complex, erythropoietin, and its derivatives, polyunsaturated fatty acids, and inhibition of secretogranin III have attracted the attention of researchers. Recently, gut microbiota modulation, non-coding RNAs, and gene therapies have shown promise in regulating ROP. These emerging therapeutics can be used to treat preterm infants with ROP.

Predicting 2-year neurodevelopmental outcomes in extremely preterm infants using graphical network and machine learning approaches

Background

Infants born extremely preterm (<28 weeks' gestation) are at high risk of neurodevelopmental impairment (NDI) with 50% of survivors showing moderate or severe NDI when at 2 years of age. We sought to develop novel models by which to predict neurodevelopmental outcomes, hypothesizing that combining baseline characteristics at birth with medical care and environmental exposures would produce the most accurate model.

Methods

Using a prospective database of 692 infants from the Preterm Epo Neuroprotection (PENUT) Trial, which was carried out between December 2013 and September 2016, we developed three predictive algorithms of increasing complexity using a Bayesian Additive Regression Trees (BART) machine learning approach to predict both NDI and continuous Bayley Scales of Infant and Toddler Development 3rd ed subscales at 2 year follow-up using: 1) the 5 variables used in the National Institute of Child Health and Human Development (NICHD) Extremely Preterm Birth Outcomes Tool, 2) 21 variables associated with outcomes in extremely preterm (EP) infants, and 3) a hypothesis-free approach using 133 potential variables available for infants in the PENUT database.

Findings

The NICHD 5-variable model predicted 3-4% of the variance in the Bayley subscale scores, and predicted NDI with an area under the receiver operator curve (AUROC, 95% CI) of 0.62 (0.56-0.69). Accuracy increased to 12-20% of variance explained and an AUROC of 0.77 (0.72-0.83) when using the 21 pre-selected clinical variables. Hypothesis-free variable selection using BART resulted in models that explained 20-31% of Bayley subscale scores and AUROC of 0.87 (0.83-0.91) for severe NDI, with good calibration across the range of outcome predictions. However, even with the most accurate models, the average prediction error for the Bayley subscale predictions was around 14-15 points, leading to wide prediction intervals. Higher total transfusion volume was the most important predictor of severe NDI and lower Bayley scores across all subscales.

Interpretation

While the machine learning BART approach meaningfully improved predictive accuracy above a widely used prediction tool (NICHD) as well as a model utilizing NDI-associated clinical characteristics, the average error remained approximately 1 standard deviation on either side of the true value. Although dichotomous NDI prediction using BART was more accurate than has been previously reported, and certain clinical variables such as transfusion exposure were meaningfully predictive of outcomes, our results emphasize the fact that the field is still not able to accurately predict the results of complex long-term assessments such as Bayley subscales in infants born EP even when using rich datasets and advanced analytic methods. This highlights the ongoing need for long-term follow-up of all EP infants.

Funding

Supported by the National Institute of Neurological Disorders and StrokeU01NS077953 and U01NS077955.

Blood products transfusion and retinopathy of prematurity: A cohort study

AIM

The aim of the study was to assess the influence of blood product transfusions on the development and severity of retinopathy of prematurity (ROP).

METHODS

A retrospective cohort study was conducted of very low birth weight (VLBW) newborns with less than 32 weeks gestational age (GA) admitted to the neonatal unit of a tertiary care hospital during the period from 1 January 2008 to 31 December 2021. Data on the degree of ROP and the transfusions received were obtained and analysed. Both univariate and multivariate analyses were performed, by logistic regression.

RESULTS

A total of 565 VLBW newborns were recruited, of whom 263 received a red blood cell transfusion prior to 36 weeks corrected GA. The newborns with ROP received significantly more red blood cell transfusions than those not presenting this condition. After adjusting for oxygen therapy and GA, the risk of ROP was found to be 2.77 times higher (95% CI 1.31-5.88) after receiving three or more transfusions, with a 3.95 times higher risk (95% CI 1.40-11.1) of developing severe ROP. Having received the first red blood cell transfusion before 32 weeks corrected GA is associated with an increased risk of ROP (OR 2.18; 95% CI: 1.09-4.36).

CONCLUSION

In VLBW neonates, the number of red blood cell transfusions and their administration before 32 weeks corrected GA are important risk factors for ROP.

Screening and Risk Factors for Retinopathy of Prematurity in a Tertiary Care Hospital in Cairo, Egypt

Purpose

To evaluate the retinopathy of prematurity (ROP) prevalence, risk factors and screening outcome in a tertiary hospital in Cairo, Egypt.

Methods

A prospective observational study was done in Neonatal Intensive Care Unit in Ain Shams University Hospital. A total of 159 premature infants were screened for ROP based on the most inclusive criteria reported to date. Screening included premature infants with gestational age (GA) of ≤34 weeks or birth weight (BW) of ≤2000 grams, or GA >34 weeks or BW >2000 grams, with multiple co-morbidities. The prevalence of ROP, plus disease and their correlation with risk factors of interest were studied.

Results

The GA of the included infants ranged from 27 to 36 weeks, mean (SD) 31.87 (± 1.81) weeks. The BW ranged from 640 to 3900 grams, mean (SD) 1784.71 (± 560.30) grams. The prevalence of ROP more than stage 0 was 25.8% (41 infants), 7.3% of the cases (11 infants) showed plus disease and 6.3% (10 infants) showed severe ROP requiring treatment. Of those, 2 cases (20%) fell outside the British Guideline's criteria for Screening. There was a highly significant (p < 0.0001) correlation between ROP more than stage 0 and low GA, low BW, mechanical ventilation, respiratory distress syndrome, necrotizing enterocolitis, intraventricular haemorrhage, and blood transfusion. No significant correlation was found between appearance of ROP more than stage 0 and gender (p = 0.911), patent ductus arteriosus (p =0.187), or sepsis (p =0.998).

Conclusion

ROP is a significant problem in the premature infants in Egypt. Extremely premature infants with lower BW are more prone to develop ROP. However, cases with higher GA and BW than mentioned in the British guidelines screening criteria especially with multiple comorbidities showed severe ROP requiring intervention, which implies the need to develop a screening guideline for the Egyptian population.

Telemedicine in retinopathy of prematurity: Crossing borders in pediatric vision health. TELEROP study

GENERAL OBJECTIVE

To evaluate the accuracy and validity of images with smartphone compared to the RetCam® system for the diagnosis of retinopathy of prematurity (ROP).

METHODOLOGY

Observational, longitudinal and masked study carried out at the Dr. Elías Santana hospital. Infants with birth weight ≤1500 g, gestational age ≤30 weeks and/or patients exposed to risk factors or complications linked to ROP were included. These subjects were screened using images with smartphone or RetCam®, both compared to conventional fundoscopy. The ICROP classification was used for staging. The main results analyzed were sensitivity, specificity, positive predictive values and kappa index.

RESULTS

915 images (n = 121) were obtained, distributed in smartphone group (50.4%) and RetCam® group (49.6%) between August 2020 and March 2021. Subjects with ROP had lower gestational age (30.2 sem ± 2.8), birth weight (1361 g ± 398), and greater exposure to oxygen therapy (12.8 days ± 11.3). The RetCam® group presented sensitivity = 80%, specificity = 78%, positive predictive value = 90% and kappa index = 0.70. The smartphone group presented sensitivity = 88%, specificity = 90%, positive predictive value = 93.75% and kappa index = 0.81.

CONCLUSIONS

Both diagnostic methods were accurate to identify ROP. The smartphone group obtained superior results with excellent resolution, representing a cost-effective method to create a global impact on reducing preventable blindness in the pediatric population.

Packed red blood cell transfusion in preterm infants

Premature infants commonly receive adult packed red blood cells (pRBCs) during their hospital stay. As adult erythrocytes differ substantially from those of preterm infants, transfusion of adult pRBCs into preterm infants can be considered inappropriate for the physiology of a preterm infant. An absence of standardisation of transfusion protocols makes it difficult to compare and interpret pertinent clinical data, as reflected by unclear associations between pRBC transfusion and complications related to prematurity, such as bronchopulmonary dysplasia, neurodevelopmental impairment, retinopathy of prematurity, or necrotising enterocolitis. The difficulty in interpreting clinical data is further increased by differences in study designs that either overestimate pRBC-associated complications of prematurity or have not yet been designed to directly link pRBC transfusions to their respective complications. Thus, neonatal transfusion practice has become an ongoing difficulty, in which differences in transfusion guidelines hinder the ability to generate comparable clinical data, and heterogeneity in clinical data prevents the implementation of standardised transfusion protocols. To overcome these issues, novel approaches with biochemical-clinical translational designs could enable clinicians to gather causal evidence instead of circumstantial correlation.

Neurosensory Alterations in Retinopathy of Prematurity: A Window to Neurological Impairments Associated to Preterm Birth

Retinopathy of prematurity (ROP) is one of the main blinding diseases affecting preterm newborns and is classically considered a vascular disorder. The premature exposure to the extrauterine environment, which is hyperoxic in respect to the intrauterine environment, triggers a cascade of events leading to retinal ischemia which, in turn, makes the retina hypoxic thus setting off angiogenic processes. However, many children with a history of ROP show persistent vision impairment, and there is evidence of an association between ROP and neurosensory disabilities. This is not surprising given the strict relationship between neuronal function and an adequate blood supply. In the present work, we revised literature data evidencing to what extent ROP can be considered a neurodegenerative disease, also taking advantage from data obtained in preclinical models of ROP. The involvement of different retinal cell populations in triggering the neuronal damage in ROP was described along with the neurological outcomes associated to ROP. The situation of ROP in Italy was assessed as well.

Incidence and Risk Factors for Retinopathy of Prematurity in a Portuguese Cohort

PURPOSE

To evaluate the incidence and risk factors for retinopathy of prematurity (ROP) in two Portuguese neonatal units with a sub-analysis of infants with a gestational age (GA) of 28 weeks or older.

METHODS

This was a retrospective case series of all infants who underwent ROP screening from 2012 to 2020. Demographic, clinical, and laboratory data were collected. Univariate logistic regression was used to examine the risk factors for ROP followed by multivariate regression.

RESULTS

A total of 475 infants were included with a median GA of 30 weeks (range: 23 to 36 weeks) and a median birth weight of 1,229 grams (range: 408 to 2,620 grams). ROP was diagnosed in 113 infants (23.8%) and 29 (6.1%) were treated. In the multivariate analysis, GA and hyperglycemia were significantly associated with severe ROP (P < .001). In the subgroup analysis of infants with a GA of 28 weeks or older, bronchopulmonary dysplasia, late-onset sepsis, and hyperglycemia were linked to severe ROP.

CONCLUSIONS

The incidence of ROP in the cohort falls within the range of other high-income countries. Hyperglycemia overpowered all of the other risk factors. Although rare, more mature infants are also at risk for severe ROP. Infants with older GA share the same group of risk factors, but bronchopulmonary dysplasia seems to play a greater role. [J Pediatr Ophthalmol Strabismus. 2022;59(4):254-260.].

Beyond Fetal Immunity: A Systematic Review and Meta-Analysis of the Association Between Antenatal Corticosteroids and Retinopathy of Prematurity

Background: Retinopathy of prematurity (ROP) is a major cause of childhood blindness. Antenatal corticosteroids (ACS) exposure is known to ameliorate the risk of and mortality of neonatal morbidities. However, the effect of ACS on ROP development is currently unknown. We conducted a meta-analysis with up-to-date evidence to assess the association between ACS exposure and the development of ROP in at-risk preterm infants.

Methods: PubMed, EMBASE, Scopus, Web of Science, and the Cochrane Library were systematically searched from inception to May 2021, supplemented with manual search from reference lists. Studies with a control group reporting ROP rate in ACS-exposed infants were included. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated utilizing a random-effects model. The Newcastle-Ottawa Scale was used for assessment of risk of bias in the included studies. Meta-regressions were performed to explore the predictive role of confounders for between-study variance.

Results: A total of 63 studies, involving 196,264 infants, were included. Meta-analysis showed ACS exposure was not associated with ROP occurrence (uOR 0.92, 95% CI 0.80–1.07; aOR 0.87, 95% CI 0.7–1.08). Results from extremely immature subgroups revealed significant reduced risks of ROP occurrence in ACS-exposed infants. ACS exposure was associated with significantly lower odds of ROP progression in adjusted analysis (aOR 0.48, 95% CI 0.26–0.89) instead of unadjusted analysis (uOR 0.86, 95% CI 0.68–1.08). Meta-regression showed birth weight and patent ductus arteriosus of the cohort were associated with ROP occurrence, sample size and study design strongly associated with ROP progression in ACS-exposed infants.

Conclusion: ACS treatment may decrease, but not prevent, the severity of ROP. Findings from severe ROP should be interpreted with caution owing to limited studies and the possibility of false-positive results. Considering the particular benefits in extremely immature infants, we recommend routine usage of ACS in mothers with threatened delivery to this particular birth cohort to prevent ROP occurrence. Future studies adjusting for major confounders are warranted to mitigate risk of bias in such observational evidence.

Transfusion-Free Survival Predicts Severe Retinopathy in Preterm Neonates

Repeated red blood cell (RBC) transfusions are thought to increase the risk for retinopathy of prematurity (ROP), likely due to a critical fetal hemoglobin (HbF) reduction. In this study, we investigated if the postmenstrual age (PMA) of neonates at transfusion influences the risk for ROP. We estimated the cumulative transfusion-free survival (TFS) in a series of 100 preterm neonates receiving one or more RBC units. TFS was calculated by censoring patients at first transfusion and expressing the time between birth and transfusion as either PMA or postnatal day. Then, we investigated if TFS predicted the occurrence of severe ROP, defined as ROP stage 3 or higher. We found that neonates with severe ROP displayed a significantly shorter TFS expressed according to their PMA (p = 0.001), with similar TFS according to postnatal days. At receiver operating characteristic (ROC) curve analysis, receiving an RBC unit before week 28 of PMA predicted severe ROP with a sensitivity of 64% and a specificity of 78%. In addition, receiving a second RBC unit before the PMA of 29 weeks predicted severe ROP with a sensitivity of 75% and a specificity of 69%. At multivariate analysis, PMA at the second transfusion was even more informative than at first transfusion and outperformed all other variables in predicting severe ROP, with an odds ratio of 4.554 (95% CI 1.332-15.573, p = 0.016). Since HbF decrease is greater after multiple RBC transfusions, it is conceivable that neonates receiving more than one unit before the PMA of 29 weeks may be exposed to a greater disturbance of retinal vascularization. Any strategy aimed at preventing the critical HbF decrease at this low age might potentially reduce the risk for severe ROP.

Reticulocyte Count: The Forgotten Factor in Transfusion Decisions for Extremely Low Birth Weight Infants

OBJECTIVE

 Extremely low birth weight (ELBW) infants often receive transfusions of packed red blood cells (PRBCs). Long-term outcomes of infants treated with liberal versus restricted transfusion criteria have been evaluated with conflicting results. Clinicians incorporate a reticulocyte count (RC) in their transfusion decisions. There is a lack of information on reference ranges for RCs in growing ELBW infants and whether infant's chronologic age or corrected gestational age (GA) generates a specific trend in the RCs. Our aim was to evaluate the levels of RCs obtained from ELBW infants over the course of the initial hospitalization.

STUDY DESIGN

 A retrospective chart review of ELBW infants treated in the neonatal intensive care unit (NICU) and had RCs performed. We analyzed the RCs to observe trends based on the chronologic age and corrected GA.

RESULTS

 A total of 738 RCs were analyzed. A positive trend in RCs that reached a peak at 32 to 34 weeks' corrected GA and then experienced a downward trend was observed.

CONCLUSION

 Our report examines a very common hematologic test that is theoretically helpful but is in need of guidelines concerning the appropriate frequency of testing and its utility in making transfusion decisions in ELBW infants.

KEY POINTS

· RCs should help in making transfusion decisions for ELBW infants.. · No current reference ranges for RC in this population.. · No current reference ranges for RC based on GA and postnatal age..

Erythropoietin is not a risk factor for severe retinopathy of prematurity among high risk preterm infants

BACKGROUND

Retinopathy of prematurity (ROP) is a developmental retinal vaso-proliferative disease and a leading cause of blindness in children. Early gestational age, low birth weight and unregulated oxygen exposure are the main risk factors for the development of ROP. There are conflicting reports of a possible association between recombinant Erythropoietin (rhEPO) use and an increased risk for the development of ROP.

OBJECTIVE

To determine whether rhEPO is an independent risk factor for the development of severe ROP among preterm infants with a gestational age of 23 to 32 weeks and a birth weight <1500 g.

METHODS

We performed a retrospective study of risk factors for ROP on a cohort of 1762 premature infants born between 2009 and 2014, half of whom received rhEPO. To examine the association between treated ROP and rhEPO, a propensity score (PS) analysis was performed using the inverse probability of treatment weighted (IPTW) approach.

RESULTS

The incidence of treated ROP was 7.3% (129/1762). PS analysis did not show an association between rhEPO and severe ROP needing treatment or ROP stage 2 or higher, in either the whole population or in the subgroup of babies born at 23 to 28 weeks gestation, in whom the incidence of severe ROP was the highest. Of 117 patients treated for Type 1 or worsening stage 3 ROP, 17 were first diagnosed after NICU discharge.

CONCLUSION

Our study showed no association between Erythropoietin use and severe ROP and highlights the importance of Ophthalmology follow up after hospital discharge.

The possible effect of pentoxifylline on development and severity of retinopathy of prematurity

BACKGROUND AND AIM

Retinopathy of prematurity (ROP) is the major ocular problem of preterm infants that occurs with abnormal proliferation of immature retinal vessels. Although pentoxifylline (PTX) was reported to inhibit vasculogenesis and neovascularization in experimental studies, there is no clinical data about the effects of PTX treatment on the development and severity of ROP. This clinical study aimed to investigate the possible effects of PTX on the development of ROP.

MATERIALS AND METHODS

A single-centre retrospective study was conducted including preterm infants who were hospitalised in the neonatal intensive care unit between 2015-2017 years. Infants were divided into two groups in terms of PTX administration for adjuvant therapy, as PTX and non-PTX groups.

RESULTS

A total of 211 infants were included in the study [gestational age 29 (27-31) weeks, birth weight 1140 (960-1340) g]. From these, 97 infants (46%) were given PTX treatment. The two groups were similar in terms of demographic data and baseline clinical characteristics. Any stage of ROP was detected in 47.4% of infants in the PTX group, which was significantly higher than those in the non-PTX group (27.2%) (p = 0.002). The incidence of advanced-stage ROP in the PTX group (10.3%) was also higher than in the non-PTX group (2.6%) (p = 0.021). Repeated usage of PTX was not found to be related to the development of ROP (p = 0.059). The time of PTX administration was similar between the ROP and no-ROP groups (median; one vs one week, p = 0.825). Surfactant therapy, duration of hospital stay, and PTX treatment were found as significant risk factors for ROP in the logistic regression analysis.

CONCLUSIONS

In contrast to the experimental studies and also promising results of PTX treatment in some neonatal morbidities, it may be associated with increased incidence and stage of ROP.

Haemoglobin Levels in Early Life among Infants with and without Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a proliferative retinal vascular disorder attributed to an ischaemic stimulus in preterm infants. Haemoglobin, the main component for oxygen transportation, may be implicated in ROP development. This retrospective study compared the mean weekly haemoglobin levels between infants with and without ROP over the first six weeks of life. Premature infants of less than 32 weeks gestational age and less than 1.5 kg birth weight were grouped into age and birth weight-matched ROP cases and controls. Weekly mean haemoglobin levels were documented. An independent t-test was used to analyze the difference in mean haemoglobin levels between infants with ROP and infants without ROP. Adjustment for confounders was performed using one-way analysis of covariance. There was a statistically significant difference in adjusted mean haemoglobin levels between the ROP and non-ROP group during the first week of life (p = 0.038). No significant intergroup differences were observed at the other weeks. Haemoglobin monitoring during the first week of postnatal life may be useful to guide ROP screening in premature infants.

Impact of early postnatal exposure of red blood cell transfusions on the severity of retinopathy of prematurity

BACKGROUND

Postnatal exposure to red blood cell transfusion (RBCT) in premature infants is an important risk factor for Retinopathy of Prematurity (ROP) progression. We hypothesized that higher number and earlier timing of RBCT are associated with worse ROP severity and result in laser treatment at an earlier postmenstrual age (PMA) in very low birth weight (≤1500 g, VLBW) infants.

METHODS

A retrospective medical record review of 631 VLBW infants over a 5-year period was performed. Demographic features and potential clinical risk factors including number of RBCT, ROP severity, and progression to laser treatment were collected to evaluate predictors of severe ROP. ANCOVA, pairwise post-hoc analyses, and multivariate regression were used to determine associations between frequency and timing of RBCT and ROP severity.

RESULTS

Of the 456 eligible infants, 61 developed severe ROP (13%). There was significant correlation between number of RBCTs and ROP severity, adjusted for gestational age and birthweight (Adjusted R2 = 0.53; p <  0.001). Compared to infants with No/Mild and Type 2 ROP, infants with Type 1 ROP received more RBCTs, with higher number of RBCTs per week during the first month of life (mean RBCT in ROP No/Mild 5.7±0.4 vs Type 2 16.3±1.8 vs Type 1 22.4±1.5, p = 0.042). Laser-treated infants received a higher number of RBCTs than non-treated infants (mean RBCT 22.3 vs. 6.5, p <  0.001) but no correlation was observed between number of RBCTs and PMA at time of laser treatment.

CONCLUSION

Higher number of RBCTs in early postnatal life of VLBW infants was associated with more severe ROP.

Endogenous erythropoietin concentrations and association with retinopathy of prematurity and brain injury in preterm infants

Background

Endogenous erythropoietin (EPO) concentrations vary widely in preterm infants and may be associated with perinatal risk factors and neurological outcomes. Erythropoietin is elevated in fetal hypoxia but is also a potential neuroprotectant.

Methods

In a prospective study of 27 infants ≤ 30 weeks gestation, serum erythropoietin concentrations were measured during the first month of life, on day 1 and weeks 1, 2, and 4, and related to perinatal risk factors and outcomes including retinopathy of prematurity and cerebral injury evaluated near term-equivalent post menstrual age using magnetic resonance imaging with quantitative scoring.

Results

Lower birth weight was associated with higher EPO concentrations throughout the first 2 weeks of life (r = -0.6, p < 0.01). Higher day 1 and week 1 EPO concentrations were associated with lower Apgar score at 1 minute (r = - 0.5) and 5 minutes (r = -0.7), respectively (p < 0.01). Higher day 1 EPO concentrations and 2-week area under the curve were associated with increased risk (p = 0.01) and severity (r = 0.5, p < 0.02) of retinopathy of prematurity. Higher EPO concentrations at 2 weeks were associated with increased total brain injury score (r = 0.5, p < 0.05).

Conclusion

Elevated endogenous erythropoietin concentrations in the first two weeks of life are associated with lower birth weight and increased risk of adverse outcomes.

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.

Effects of blood sampling stewardship and erythropoietin administration in extremely low birth weight infants-a quality improvement non-controlled before-and-after retrospective study

The majority of extremely low birth weight (ELBW) neonates receive red blood cell (RBC) transfusions; at least 50% receive multiple transfusions. Anemia care bundles could be the most effective approach to reduce transfusion rates. We conducted a quality improvement non-controlled before-and-after retrospective study involving 345 ELBW infants admitted over a 5-year period in two consecutive epochs before and after implementation of an anemia care bundle in January 2017. Bundle components included (a) prophylactic subcutaneous erythropoietin twice each week (600 IU/kg/week) from day 7 through 8 weeks of age and (b) blood sampling stewardship in the first five postnatal weeks. Early postnatal blood sampling losses were significantly reduced following the implementation of the care bundle (21.2 ml/kg vs 25 ml/kg, P < 0.001). We found a 50% reduction in the rate of multiple RBC transfusions (adjusted RR 0.45, 95% CI: 0.34-0.59) and a reduced odds of necrotizing enterocolitis (NEC) (4% vs 10%, adjusted OR 0.38 (95% CI: 0.15-0.78)) among infants that received the anemia care bundle (n = 182 infants). The overall transfusion rate, number and volume of transfusions, and multiple donor exposures were also significantly reduced.Conclusion: The combination of extended subcutaneous erythropoietin administration and reduced early postnatal blood sampling was associated with a significant reduction in the rate of multiple erythrocyte transfusions and NEC in ELBW neonates. What is known: • The majority of extremely low birth weight neonates continue to require blood transfusions despite advances in standardized transfusion practices; at least 50% require multiple transfusions. • Anemia care bundles, employing a combination of anemia prevention strategies, can effectively reduce the RBC transfusion rates in ELBW infants. What is new: • A combination of extended subcutaneous erythropoietin supplementation and blood sampling stewardship practices reduced the rate of multiple RBC transfusions in ELBW neonates by 50%. • Implementation of the anemia care bundle was associated with a significant reduction in the rates of necrotizing enterocolitis.

Hemodynamics of different volumes of red blood cell transfusion in preterm infants

BACKGROUND

Although many controversies exist regarding the risk of red blood cell (RBC) transfusions, half of preterm infants born at <32 weeks of gestational age receive such transfusions because of anemia of prematurity. Because of the costs and risks associated with multiple transfusions, it has been suggested that a large transfusion volume reduces the number of transfusions. However, there have been persistent concerns that RBC transfusion might lead to volume overload.

METHODS

We examined the impacts of large (20 mL/kg) compared to standard volume (15 mL/kg) transfusions on the hemodynamic variables of stable, electively transfused, preterm infants, by serially measuring echocardiographic parameters and plasma B-type natriuretic peptide levels.

RESULTS

A total of 39 infants born at <34 weeks of gestation and aged >2 weeks at the time of enrollment were randomly allocated to either a standard volume (15 mL/kg) or a large volume (20 mL/kg) group. Significant reductions in cardiac output and transient increases in plasma B-type natriuretic peptide levels were found after RBC transfusion in both the standard and large volume (20 mL/kg) groups. However, these changes were not significantly different between the two groups.

CONCLUSIONS

Large-volume transfusions could be tolerable in stable preterm infants with anemia.

Low fraction of fetal haemoglobin is associated with retinopathy of prematurity in the very preterm infant

Background

Blood loss and adult blood transfusions are common during the neonatal period in preterm infants. The objective of the study was to clarify if degree of loss of fetal haemoglobin (HbF) was associated with later retinopathy of prematurity (ROP).

Methods

Retrospective observational cohort study. In total, 452 infants born <30 gestational weeks at a tertiary level neonatal intensive care unit in Sweden in 2009–2015 were included, 385 of whom had final ROP outcome. Mean fractions of HbF (%) during the first postnatal week were calculated from 11 861 arterial blood gas analyses. The relationship between fractions of HbF (%) and ROP was evaluated.

Results

The mean (SD) gestational age (GA) at birth was 26.4 (1.8) weeks. In total, 104 (27 %) infants developed ROP. Higher fraction of HbF (%) was associated with a lower prevalence of ROP, OR by a 10% increase 0.83 (95% CI: 0.71 to 0.97; p=0.019), following adjustment for GA at birth, small for GA and sex. Infants with HbF (%) in the lowest quartile had OR of 22.0 (95% CI: 8.1 to 59.2; p<0.001) for ROP development compared with those in the highest quartile. The predictive ability (area under the curve) of HbF (%) in the full model during the first week was 0.849 for ROP.

Conclusions

Early low fraction of HbF is independently associated with abnormal retinal neurovascular development in the very preterm infant. The potential benefit of minimising blood loss on development of ROP will be investigated in a multicenter randomised trial (NCT04239690).

Transfusions and neurodevelopmental outcomes in extremely low gestation neonates enrolled in the PENUT Trial: a randomized clinical trial

BACKGROUND

Outcomes of extremely low gestational age neonates (ELGANs) may be adversely impacted by packed red blood cell (pRBC) transfusions. We investigated the impact of transfusions on neurodevelopmental outcome in the Preterm Erythropoietin (Epo) Neuroprotection (PENUT) Trial population.

METHODS

This is a post hoc analysis of 936 infants 24-0/6 to 27-6/7 weeks' gestation enrolled in the PENUT Trial. Epo 1000 U/kg or placebo was given every 48 h × 6 doses, followed by 400 U/kg or sham injections 3 times a week through 32 weeks postmenstrual age. Six hundred and twenty-eight (315 placebo, 313 Epo) survived and were assessed at 2 years of age. We evaluated associations between BSID-III scores and the number and volume of pRBC transfusions.

RESULTS

Each transfusion was associated with a decrease in mean cognitive score of 0.96 (95% CI of [-1.34, -0.57]), a decrease in mean motor score of 1.51 (-1.91, -1.12), and a decrease in mean language score of 1.10 (-1.54, -0.66). Significant negative associations between BSID-III score and transfusion volume and donor exposure were observed in the placebo group but not in the Epo group.

CONCLUSIONS

Transfusions in ELGANs were associated with worse outcomes. We speculate that strategies to minimize the need for transfusions may improve outcomes.

IMPACT

Transfusion number, volume, and donor exposure in the neonatal period are associated with worse neurodevelopmental (ND) outcome at 2 years of age, as assessed by the Bayley Infant Scales of Development, Third Edition (BSID-III). The impact of neonatal packed red blood cell transfusions on the neurodevelopmental outcome of preterm infants is unknown. We speculate that strategies to minimize the need for transfusions may improve neurodevelopmental outcomes.

Associations between Red Blood Cell and Platelet Transfusions and Retinopathy of Prematurity

AIM

The aim of this study is to examine possible associations between the transfusion of RBC or platelets (PLTs) and the development of retinopathy of prematurity (ROP) in infants.

METHODS

This retrospective, national, case-control study included all live births in Switzerland between 2013 and 2018. We investigated preterm infants at a gestational age of <28 weeks, who developed higher stage ROP (≥stage 2, n = 178). Each case infant was matched to another of the same sex who did not develop ROP (n = 178, control group).

RESULTS

When compared with the control group, we observed higher numbers of RBC transfusions per infant and higher percentages of infants receiving PLT transfusions in the case group. An adjusted logistic regression analysis revealed that both RBC (odds ratio [OR] 1.081, 95% confidence interval [CI] 1.020-1.146) and PLT transfusions (OR = 2.502, 95% CI 1.566-3.998) numbers were associated with ROP development.

CONCLUSIONS

Multiple RBC and PLT transfusions are associated with higher stage ROP development. Prospective studies are required to determine their potential as risk factors.

Preoperative Blood Transfusions and Morbidity in Neonates Undergoing Surgery

BACKGROUND

Blood transfusions in the neonatal patient population are common, but there are no established guidelines regarding transfusion thresholds. Little is known about postoperative outcomes in neonates who receive preoperative blood transfusions (PBTs).

METHODS

Using the American College of Surgeons National Surgical Quality Improvement Program-Pediatric Participant Use Data Files from 2012 to 2015, we identified all neonates who underwent surgery. Mortality and composite morbidity (defined as any postoperative complication) in neonates who received a PBT within 48 hours of surgery were compared with that in neonates who did not receive a transfusion.

RESULTS

A total of 12 184 neonates were identified, of whom 1209 (9.9%) received a PBT. Neonates who received a PBT had higher rates of preoperative comorbidities and worse postoperative outcomes when compared with those who did not receive a transfusion (composite morbidity: 46.2% vs 16.2%; P < .01). On multivariable regression analysis, PBTs were independently associated with increased 30-day morbidity (odds ratio [OR] = 1.90; 95% confidence interval [CI]: 1.63-2.22; P < .01) and mortality (OR = 1.98; 95% CI: 1.55-2.55; P < .01). In a propensity score-matched analysis, PBTs continued to be associated with increased 30-day morbidity (OR = 1.53; 95% CI: 1.29-1.81; P < .01) and mortality (OR = 1.58; 95% CI: 1.24-2.01; P = .01).

CONCLUSIONS

In a propensity score-matched model, PBTs are independently associated with increased morbidity and mortality in neonates who undergo surgery. Prospective data are needed to better understand the potential effects of a red blood cell transfusion in this patient population.

High-Dose Erythropoietin in Extremely Low Gestational Age Neonates Does Not Alter Risk of Retinopathy of Prematurity

INTRODUCTION

The Preterm Erythropoietin (Epo) Neuroprotection (PENUT) Trial sought to determine the safety and efficacy of early high-dose Epo as a potential neuroprotective treatment. We hypothesized that Epo would not increase the incidence or severity of retinopathy of prematurity (ROP).

METHODS

A total of 941 infants born between 24-0/7 and 27-6/7 weeks' gestation were randomized to 1,000 U/kg Epo or placebo intravenously for 6 doses, followed by subcutaneous or sham injections of 400 U/kg Epo 3 times a week through 32 weeks post-menstrual age. In this secondary analysis of PENUT trial data, survivors were evaluated for ROP. A modified intention-to-treat approach was used to compare treatment groups. In addition, risk factors for ROP were evaluated using regression methods that account for multiples and allow for adjustment for treatment and gestational age at birth.

RESULTS

Of 845 subjects who underwent ROP examination, 503 were diagnosed with ROP with similar incidence and severity between treatment groups. Gestational age at birth, birth weight, prenatal magnesium sulfate, maternal antibiotic exposure, and presence of heart murmur at 2 weeks predicted the development of any ROP, while being on high-frequency oscillator or high-frequency jet ventilation (HFOV/HFJV) at 2 weeks predicted severe ROP.

CONCLUSION

Early high-dose Epo followed by maintenance dosing through 32 weeks does not increase the risk of any or severe ROP in extremely low gestational age neonates. Gestational age, birth weight, maternal treatment with magnesium sulfate, antibiotic use during pregnancy, and presence of a heart murmur at 2 weeks were associated with increased risk of any ROP. Treatment with HFOV/HFJV was associated with an increased risk of severe ROP.

Effect of High-Dose Erythropoietin on Blood Transfusions in Extremely Low Gestational Age Neonates: Post Hoc Analysis of a Randomized Clinical Trial

IMPORTANCE

Extremely preterm infants are among the populations receiving the highest levels of transfusions. Erythropoietin has not been recommended for premature infants because most studies have not demonstrated a decrease in donor exposure.

OBJECTIVES

To determine whether high-dose erythropoietin given within 24 hours of birth through postmenstrual age of 32 completed weeks will decrease the need for blood transfusions.

DESIGN, SETTING, AND PARTICIPANTS

The Preterm Erythropoietin Neuroprotection Trial (PENUT) is a randomized, double-masked clinical trial with participants enrolled at 19 sites consisting of 30 neonatal intensive care units across the United States. Participants were born at a gestational age of 24 weeks (0-6 days) to 27 weeks (6-7 days). Exclusion criteria included conditions known to affect neurodevelopmental outcomes. Of 3266 patients screened, 2325 were excluded, and 941 were enrolled and randomized to erythropoietin (n = 477) or placebo (n = 464). Data were collected from December 12, 2013, to February 25, 2019, and analyzed from March 1 to June 15, 2019.

INTERVENTIONS

In this post hoc analysis, erythropoietin, 1000 U/kg, or placebo was given every 48 hours for 6 doses, followed by 400 U/kg or sham injections 3 times a week through postmenstrual age of 32 weeks.

MAIN OUTCOMES AND MEASURES

Need for transfusion, transfusion numbers and volume, number of donor exposures, and lowest daily hematocrit level are presented herein.

RESULTS

A total of 936 patients (488 male [52.1%]) were included in the analysis, with a mean (SD) gestational age of 25.6 (1.2) weeks and mean (SD) birth weight of 799 (189) g. Erythropoietin treatment (vs placebo) decreased the number of transfusions (unadjusted mean [SD], 3.5 [4.0] vs 5.2 [4.4]), with a relative rate (RR) of 0.66 (95% CI, 0.59-0.75); the cumulative transfused volume (mean [SD], 47.6 [60.4] vs 76.3 [68.2] mL), with a mean difference of -25.7 (95% CI, 18.1-33.3) mL; and donor exposure (mean [SD], 1.6 [1.7] vs 2.4 [2.0]), with an RR of 0.67 (95% CI, 0.58-0.77). Despite fewer transfusions, erythropoietin-treated infants tended to have higher hematocrit levels than placebo-treated infants, most noticeable at gestational week 33 in infants with a gestational age of 27 weeks (mean [SD] hematocrit level in erythropoietin-treated vs placebo-treated cohorts, 36.9% [5.5%] vs 30.4% [4.6%] (P < .001). Of 936 infants, 160 (17.1%) remained transfusion free at the end of 12 postnatal weeks, including 43 in the placebo group and 117 in the erythropoietin group (P < .001).

CONCLUSIONS AND RELEVANCE

These findings suggest that high-dose erythropoietin as used in the PENUT protocol was effective in reducing transfusion needs in this population of extremely preterm infants.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01378273.

Predictors and ocular outcomes of rescue treatment in preterm infants with treated retinopathy of prematurity-a retrospective study

AIM

To determine predictors of rescue treatment among infants treated for retinopathy of prematurity and to evaluate their ocular outcomes at 18-24 months of corrected age.

METHODS

This is a single centre retrospective study of infants who received treatment for type 1 ROP, using laser photocoagulation or anti VEGF agents. Multivariable logistic regression was used to generate a prediction model for rescue treatment of ROP. The primary outcome was an abnormal refractive outcome by 24 months of corrected age, among infants primarily treated with laser therapy.

RESULTS

Two hundred and eight infants (including 416 eyes) who received single (n = 151) or rescue (multiple) treatments (n = 57) were included. Ninety three percent of the infants were primarily treated with laser photocoagulation. Lower gestational age, small for gestational age, early packed red blood cell transfusion (within 2 weeks of postnatal age), and presence of Zone 1 retinopathy predicted the need for rescue treatment in treated infants [area under the receiver operating characteristic curve: 0.81 (0.73-0.89)]. The incidence of abnormal refractive outcome, assessed in a total of 174 infants, was found to be significantly higher in the rescue treatment group (67% versus 21%, adjusted odds ratio: 7.56 (3.3-17.2), P < 0.001). Myopia, very high myopia and use of spectacles was significantly higher in the rescue treatment group (P < 0.001 for each).

CONCLUSIONS

Rescue treatment for ROP was associated with an increased incidence of refractive errors and requirement of spectacles by 2 years of age. Larger prospective multicentre studies are required to confirm the findings from our study.

Umbilical cord blood: Current uses for transfusion and regenerative medicine

The past 20 years of experience with umbilical cord blood transplantation have demonstrated that cord blood is effective in the treatment of a spectrum of diseases, including hematological malignancies, bone marrow failure, hemoglobinopathies, and inborn errors of metabolism. However, only a few number of umbilical cord blood units collected have a cell content adequate for an allogenic hematopoietic stem cell transplantation. In the meanwhile, there is an increasing interest in exploiting cord blood derivatives in different fields. In this review, we will summarize the most recent updates on clinical applications of umbilical cord blood platelet derivatives for regenerative medicine, and we will revise the literature concerning the use of umbilical cord blood for autologous or allogeneic transfusion purposes. The methodological aspect and the biological characteristics of these products also will be discussed.

Allogeneic cord blood transfusions prevent fetal haemoglobin depletion in preterm neonates. Results of the CB-TrIP study

Repeated red blood cell (RBC) transfusions in preterm neonates are associated with poor outcome and increased risk for prematurity-associated diseases. RBC transfusions cause the progressive replacement of fetal haemoglobin (HbF) by adult haemoglobin (HbA). We monitored HbF levels in 25 preterm neonates until 36 weeks of post-menstrual age (PMA); patients received RBC units from allogeneic cord blood (cord-RBCs) or from adult donors (adult-RBCs), depending on whether cord-RBCs were available. Primary outcome was HbF level at PMA of 32 weeks. Twenty-three neonates survived until this age: 14 received no transfusions, two only cord-RBCs, three only adult-RBCs and four both RBC types. HbF levels in neonates transfused with cord-RBCs were significantly higher than in neonates receiving adult-RBCs (P < 0·0001) or both RBC types (P < 0·0001). Superimposable results were obtained at PMA of 36 weeks. Every adult-RBCs transfusion increased the risk for an HbF in the lowest quartile by about 10-fold, whereas this effect was not evident if combined adult- and cord-RBCs were evaluated. Overall, these data show that transfusing cord-RBCs can limit the HbF depletion caused by conventional RBC transfusions. Transfusing cord blood warrants investigation in randomised trials as a strategy to mitigate the severity of retinopathy of prematurity (NCT03764813).