Umbilical Cord Blood-An Untapped Resource: Strategies to Decrease Early Red Blood Cell Transfusions and Improve Neonatal Outcomes

Cord Platelet Count of Full-Term Neonates in Relation to ABO Incompatibility and Glucose-6-Phosphate Dehydrogenase Levels: A Retrospective Cohort Study

Background The immunoglobulin G of mothers with O blood type may sensitize the platelets of their neonates with A (O-A incompatibility) or B (O-B incompatibility) blood type. As the expression and antigenicity of the B antigen on platelets is less than that of the A antigens, we have hypothesized that platelet count is higher in the O-B incompatibility group compared to the O-A incompatibility group. There is controversy about whether glucose-6-phosphate dehydrogenase (G6PD) deficiency, without evidence of hemolysis, is associated with a lower platelet count than G6PD-normal. Aim To assess whether platelet count is higher in the O-B than in the O-A incompatible neonates and whether it correlates with their G6PD levels. Methods This study was a retrospective cohort study on a sample of 835 healthy neonates born at ≥38 weeks gestation who were either A or B blood types with mothers that carried the blood type O Rh-positive. The platelet count (thousand per microliter) from umbilical cord venous blood (UCVB) was used. A G6PD level of 11.0 units/gram of hemoglobin (U/g Hb) was considered the lower reference limit. G6PD deficiency was defined as a G6PD level of <3.3 U/g Hb in both sexes. Intermediate G6PD deficiency in females was described as a G6PD level of 3.3-8.8 U/g Hb. Results The mean UCVB platelet count was higher in female neonates compared to male neonates (n=389, 283±65 versus n=446, 272±73, p=0.01). The mean UCVB platelet count was higher in the O-B incompatibility group in both male (n=114, 291±82 versus n=103, 266±63) and female neonates (n=83, 303±66 versus n=81, 278±58) with G6PD levels of >8.8 U/g Hb. There was a positive weak correlation between UCVB platelet counts and G6PD levels only in O-B incompatible female neonates (n=176, r=0.23, p=0.002). The partitioning and combined 95% reference intervals (RIs) of the UCVB platelet count were presented. Conclusion The platelet count was higher in the O-B incompatibility group compared to the O-A incompatibility group, but only when the G6PD level was >8.8 U/g Hb. A correlation between UCVB platelet count and G6PD levels was found only among O-B incompatible female neonates. These findings may have an important implication in estimating RIs of the UCVB platelet count, however, they need to be confirmed and explored in future research.

Utilizing umbilical cord blood - Minimizing blood sampling and pain in healthy infants at risk for polycythemia

BACKGROUND

Exposure to pain in early life was associated with long term consequences, therefore strategies for minimizing painful procedures in newborns should be employed. The utility and reliability of cord blood CBC was demonstrated before, however data regarding use of cord blood in healthy infants at risk for polycythemia are lacking.

METHODS

A single-center, paired-sampling prospective laboratory study including all healthy asymptomatic infants born after 36 weeks gestation who were SGA (<2500 g), LGA (>4000 g), or born to mothers with diabetes in pregnancy. Blood count indices were compared between umbilical and neonatal capillary or venous blood samples. In order to predict cut-off values for neonatal polycythemia using umbilical hematocrit, receiver operator curves (ROC) were plotted.

RESULTS

Paired samples were collected from 433 infants. Mean gestational age and birth-weight were 39.0 ± 1.3 weeks and 3489 ± 682 g. Hemoglobin, hematocrit and WBC values were lower in cord blood compared to neonatal, but PLT count was higher. Pearson r showed only modest correlation between peripheral capillary and umbilical or venous Hct - 0.35 (p < 0.001), and 0.44 (p < 0.001), respectively. In order to try and capture clinically significant polycythemia ROC was plotted for hematocrit >70% and <40%. In our cohort, using the calculated cutoff values (>51% and <35%) could have resulted in a decrease of 72% of neonatal blood draws.

CONCLUSION

This analysis should be interpreted with caution, as currently it cannot support the routine use of umbilical samples' hematocrits for making treatment decision in newborns at risk for polycythemia. Further larger studies are needed.

Primary hemostasis in fetal growth restricted neonates studied via PFA-100 in cord blood samples

BACKGROUND

Platelet function of fetal growth restricted (FGR) neonates remains a field of debate. Platelet function analyzer (PFA-100) offers a quantitative in vitro assessment of primary, platelet-related hemostasis. Our aim was to examine platelet function using PFA-100 in FGR neonates and associate our results with perinatal parameters.

METHODS

PFA-100 was applied on 74 FGR neonates, 48 full-term (>37 weeks' gestation) and 26 preterm neonates (<37 weeks). The control group consisted of 118 healthy neonates. Two closure times (CTs) with COL/EPI and COL/ADP cartridges were determined on cord blood samples for each subject. Statistical analysis was performed by SAS 9.4. The statistical significance level was set at 0.05 and all tests were two-tailed.

RESULTS

COL/EPI CTs were prolonged in FGR (median 132 s, IQR 95-181 s) compared with control neonates (median 112.5 s, IQR 93-145 s), p = 0.04. Median COL/EPI CT for term and preterm FGR neonates was 126 s (IQR 90-157 s) and 137 s (IQR 104-203), respectively (p = 0.001), and COL/ADP CT was 70 s (IQR 62-80 s) for term and 75 s (IQR 68-82 s) for preterm FGR neonates (p = 0.08). Among FGR neonates, COL/EPI CT was related with delivery time (with preterm neonates exhibiting prolonged COL/EPI CTs), p = 0.05. No correlation was proved between both CTs and hematological parameters in FGR neonates.

CONCLUSION

FGR neonates showed impaired platelet function via PFA-100, with preterm FGR neonates confronting the greatest risk. Prolonged COL/EPI CTs in FGR neonates seemed to be independent of hematological parameters and could warn for closer evaluation during the first days of their lives.

Feasibility and accuracy of cord blood sampling for admission laboratory investigations: A pilot trial

AIM

Phlebotomy losses greatly contribute to anaemia following preterm birth. Therefore, the possibility of drawing initial tests from the placenta seems attractive. There is a lack of literature regarding the feasibility and accuracy of pathology tests taken from umbilical arterial and venous (UAB/UVB) compared to blood collected from the newborn.

METHODS

UAB and UVB complete blood pictures were compared with the initial neonatal blood test. The relationship between UAB, UVB and neonatal complete blood picture values was determined by Spearman's Rho correlation with absolute values compared by Kruskal-Wallis. P < 0.05 was considered significant.

RESULTS

Neonatal haemoglobin, white cell count, immature/total ratio and platelets were significantly correlated to the corresponding values in the UAB and UVB (all P < 0.001). While UAB and UVB haemoglobin and white cell count were similar, both were significantly lower than the neonatal values (P < 0.001 and P = 0.014, respectively). No difference was seen for immature/total ratio and platelet concentrations. UVB blood culture (BC) was feasible (90%), even with delayed cord clamping, and the UVB BC volume was significantly higher (P < 0.001), with a low rate of BC contamination (1.5%).

CONCLUSIONS

Our findings support the feasibility and accuracy of umbilical blood in place of blood collected from the newborn. This reduces the phlebotomy losses and allows higher blood volume collection which may increase the sensitivity of BC collection.

Interventions to minimize blood loss in very preterm infants-A systematic review and meta-analysis

Blood loss in the first days of life has been associated with increased morbidity and mortality in very preterm infants. In this systematic review we included randomized controlled trials comparing the effects of interventions to preserve blood volume in the infant from birth, reduce the need for sampling, or limit the blood sampled. Mortality and major neurodevelopmental disabilities were the primary outcomes. Included studies underwent risk of bias-assessment and data extraction by two review authors independently. We used risk ratio or mean difference to evaluate the treatment effect and meta-analysis for pooled results. The certainty of evidence was assessed using GRADE. We included 31 trials enrolling 3,759 infants. Twenty-five trials were pooled in the comparison delayed cord clamping or cord milking vs. immediate cord clamping or no milking. Increasing placental transfusion resulted in lower mortality during the neonatal period (RR 0.51, 95% CI 0.26 to 1.00; participants = 595; trials = 5; I2 = 0%, moderate certainty of evidence) and during first hospitalization (RR 0.70, 95% CI 0.51, 0.96; 10 RCTs, participants = 2,476, low certainty of evidence). The certainty of evidence was very low for the other primary outcomes of this review. The six remaining trials compared devices to monitor glucose levels (three trials), blood sampling from the umbilical cord or from the placenta vs. blood sampling from the infant (2 trials), and devices to reintroduce the blood after analysis vs. conventional blood sampling (1 trial); the certainty of evidence was rated as very low for all outcomes in these comparisons. Increasing placental transfusion at birth may reduce mortality in very preterm infants; However, extremely limited evidence is available to assess the effects of other interventions to reduce blood loss after birth. In future trials, infants could be randomized following placental transfusion to different blood saving approaches. Trial registration: PROSPERO CRD42020159882.

Iron Homeostasis Disruption and Oxidative Stress in Preterm Newborns

Iron is an essential micronutrient for early development, being involved in several cellular processes and playing a significant role in neurodevelopment. Prematurity may impact on iron homeostasis in different ways. On the one hand, more than half of preterm infants develop iron deficiency (ID)/ID anemia (IDA), due to the shorter duration of pregnancy, early postnatal growth, insufficient erythropoiesis, and phlebotomy losses. On the other hand, the sickest patients are exposed to erythrocytes transfusions, increasing the risk of iron overload under conditions of impaired antioxidant capacity. Prevention of iron shortage through placental transfusion, blood-sparing practices for laboratory assessments, and iron supplementation is the first frontier in the management of anemia in preterm infants. The American Academy of Pediatrics recommends the administration of 2 mg/kg/day of oral elemental iron to human milk-fed preterm infants from one month of age to prevent ID. To date, there is no consensus on the type of iron preparations, dosages, or starting time of administration to meet optimal cost-efficacy and safety measures. We will identify the main determinants of iron homeostasis in premature infants, elaborate on iron-mediated redox unbalance, and highlight areas for further research to tailor the management of iron metabolism.

Is placental blood a reliable source for the evaluation of neonatal hemostasis at birth?

BACKGROUND

Phlebotomy is among the main determinants of anemia of prematurity. Blood sparing policies endorsed umbilical cord blood (here called placental) as an alternative source for laboratory testing. Little is known on the suitability of placental blood to evaluate neonatal hemostasis of newborn infants. We aimed to compare the hemostatic profile of paired placental and infant venous blood, by means of prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, antithrombin, protein C, thromboelastography (TEG) and thrombin generation assay (TGA).

STUDY DESIGN

This was an observational single-center study.

METHODS

We collected at birth venous citrated blood from both placental and infant venous source and performed PT, APTT, fibrinogen, antithrombin, protein C, TEG (reaction time-R; kinetics-K alpha angle-α, maximum amplitude-MA and lysis at 30 minutes-LY30), and TGA (endogenous thrombin potential-ETP).

RESULTS

We enrolled 60 neonates with a median gestational age (range) of 37 weeks (28⁺¹ -41) and birth-weight 2417 g (950-4170). Based on TEG and TGA, placental blood showed a procoagulant imbalance as indicated by lower median R (4.0 vs. 6.1 min; p < 0.001) and K (1.3 vs. 2.2 min; p < 0.001); higher α-angle (69.7 vs. 57.4°; p < 0.001) and ETP (1260 vs. 1078; p = 0.002) than those observed for infant venous blood. PT and APTT did not differ significantly between the two groups.

CONCLUSIONS

While placental and neonatal blood samples are equally suitable to measure the standard coagulation tests PT and APTT, placental blood leads to a procoagulant imbalance when testing is performed with TEG or TGA. These effects should be considered when interpreting results stemming from investigation of neonatal hemostasis.

Can Fetal Umbilical Venous Blood Be a Reliable Source for Admission Complete Blood Count and Culture in NICU Patients?

BACKGROUND

Minimizing initial neonatal blood draws and their associated pain is important. The placenta has ample fetal blood that is otherwise discarded; obtaining admission laboratory evaluations from fetal umbilical venous blood (FUVB) may provide a suitable alternative.

OBJECTIVE

We hypothesized that obtaining an aerobic bacterial blood culture (BCX) and a complete blood count with manual differential (CBC/diff) from FUVB is feasible and yields results comparable to those obtained directly from the neonate.

STUDY DESIGN

BCX and CBC/diff were attempted on paired samples from FUVB (in the delivery room) and neonatal blood (shortly after NICU admission) of 110 patients. The paired t test, Pearson's correlation coefficient (R), and multivariable linear regression were used for data analysis.

RESULTS

Positive BCXs were found in 9 of 108 FUVB samples compared to 1 of 91 neonatal samples. Three out of 9 FUVB cultures were true pathogens, including 2 Escherichia coli and 1 viridans group streptococcus, all with negative corresponding paired neonatal cultures. There was 1 positive neonatal BCX, E. coli, with a negative paired FUVB culture. Neonatal hemoglobin (Hb), platelets (PLT), and white blood cells (WBC) all significantly (p < 0.0001) correlated with the paired FUVB samples (R = 0.50, 0.49, and 0.84, respectively). Hb, PLT, and WBC values were clinically comparable but statistically higher in neonatal blood (the differences were 2.3 g/dL, 30,000 cells/μL, and 2,800 cells/μL, respectively; p < 0.007 for all comparisons).

CONCLUSIONS

FUVB is suitable for obtaining CBC/diff. FUVB is an appropriate second source for BCX as it yields additional true pathogens. Our findings may support the presence of "culture-negative sepsis" in some neonates.

Comparison of Placental and Neonatal Admission Complete Blood Cell Count and Blood Cultures

BACKGROUND

The utilization of placental blood for neonatal admission laboratory tests, specifically the complete blood cell (CBC) count and blood culture, has the potential to delay the onset of anemia of prematurity and intraventricular hemorrhage, frequency of blood transfusions and associated complications, and painful procedures related to laboratory sampling.

PURPOSE

To determine the feasibility of drawing neonatal admission laboratory tests from the placenta rather than the neonate and to compare CBC count and blood culture results.

METHODS

All infants less than 35 weeks' gestational age and all term infants with a maternal history of chorioamnionitis or untreated, positive group B Streptococcus status were eligible to participate. Participating infants had paired CBC count and blood cultures obtained from the placenta and the infant.

RESULTS

All CBC count outcomes were significantly, positively correlated between placental and infant blood (all Ps < .05). The paired white blood cells, neutrophils, and lymphocytes were strongly correlated (r = 0.761, r = 0.797, and r = 0.815, respectively), whereas the hemoglobin, hematocrit, platelet, and eosinophils were moderately correlated (r = 0.554, r = 0.545, r = 0.563, and r = 0.478, respectively). Monocytes and basophils were only weakly correlated (r = 0.373 and r = 0.217, respectively). There were 13 (93%) pairs where placental blood culture was positive but the direct infant draw blood culture was negative, and 1 (7%) pair where the placental culture was negative but the direct infant draw blood culture was positive.

IMPLICATIONS FOR PRACTICE

The results of this and other studies suggest that placental blood can be reliably used to obtain neonatal admission CBC count and blood cultures.

IMPLICATIONS FOR RESEARCH

Further research is needed regarding the prevention of blood culture contamination, especially in vaginally delivered placentas. Institutions that adopt this procedure should perform quality improvement initiatives to monitor outcomes and add to the growing body of literature on the utilization of placental blood for neonatal admission laboratory tests.

Use of Placental/Umbilical Blood Sampling for Neonatal Admission Blood Cultures: Benefits, Challenges, and Strategies for Implementation

Placental blood remains an underused resource for early neonatal care despite ample evidence that placental blood provides the same clinical decision making information without the need for painful, invasive blood sampling procedures. Potential benefits of placental/umbilical blood sampling (PUBS) for neonatal admission labs include decreases in pain reactivity, rates of anemia, need for blood transfusions, use of vasopressors, and rates of intraventricular hemorrhage. Here, we present a unique case study of a critically ill infant with contradictory blood culture results from PUBS and direct infant sampling. A negative admission direct sample blood culture result compared with a positive admission PUBS blood culture result suggests that infection may have been missed in the direct infant sample. Relevant placental embryology and circulation is also described, as well as the benefits of PUBS for neonatal admission labs (with focus on the blood culture), challenges associated with PUBS practice, and strategies for implementation of PUBS.

Prevention of the anaemia of prematurity

Despite recent advances in neonatal and perinatal medicine, extremely low birth weight infants (ELBW) are at high risk of developing anaemia of prematurity (AOP) requiring packed red blood cell (RBC) transfusions. The benefit of transfusing allogenic RBCs for AOP is a controversial issue, except for disturbances in tissue oxygenation. Although the role of erythropoietin (EPO) in the pathophysiology of AOP is well known, neither early nor late recombinant human EPO therapy alters the number or volume of RBC transfusions. It is also known that one-half of the feto-placental blood volume remains outside the newborn infant's circulation at 30 weeks of gestation if the umbilical cord is clamped immediately. Delayed cord clamping (DCC) and umbilical cord milking (UCM) are the main methods for enhancing placental transfusion. The basic principle of these approaches depends on providing high haemoglobin (Hb) levels to premature infants in the delivery room. The enhancement of placental transfusion clearly results in higher Hb levels at birth, reducing the need for RBC transfusions as well as creating a better haemodynamic status during the initial hours of life. To date, enhancement of placental transfusion in the delivery room by either DCC or UCM seems to be the best preventive measure for AOP. Yet, studies on the associated neurodevelopmental outcomes are insufficient to reach a conclusion. This review summarizes the pathophysiology, treatment and preventative strategies of anaemia of prematurity in light of the current literature.