The correlation between automated hematology and manually read smears for the determination of nucleated red blood cells in umbilical cord blood

Objective.?To determine the correlation between automated hematology nucleated red blood cell counts and manual counts in umbilical cord blood.

Methods.?Umbilical cord venous blood was obtained after cord clamping at the time of delivery. The number of nucleated red blood cells per one hundred white blood cells was measured using an automated hematology analyzer and compared with direct microscopic visualization of prepared slides by experienced hematology technicians.

Results.?The umbilical cord blood from 128 women was studied. The mean, median and standard deviations of nucleated red blood cell counts were not significantly different between the automated reading and the manual reading (mean 9.3?±?11.2 versus 9.1?±?13.1, respectively, P?=?0.76; median 5.9 versus 5.0, P?=?0.95; range 0–77, 0–105). Automated derived nucleated red blood cell counts and manual numbers were highly correlated with a correlation coefficient of 0.794.

Conclusion.?The automated hematology analyzer readings of nucleated red blood cell counts correlate well with readings by laboratory hematologists.     

Nucleated red blood cells in cord blood of singleton term and post-term neonates

OBJECTIVE: This study aims to determine if nucleated red blood cells are elevated in pregnancies that continue beyond 289 days of gestation. STUDY DESIGN: Cord blood was prospectively collected from term and post-term singleton gestations from August 1 to December 31, 1998. Umbilical artery nucleated red blood cells were counted per 100 white blood cells. The comparison was made between pregnancies ending at 261-289 days (37.1-41.2 weeks) of gestation and those ending after 289 days (> or = 41.3 weeks) of gestation. RESULTS: Cord blood from 304 cases was obtained and evaluated for nucleated red blood cells per 100 white blood cells. The mean value of nucleated red blood cells per 100 white blood cells in the post-term neonate group was significantly higher than in the term neonate group (median 6.5, range 0-24 vs. median 3.7, range 0-14; p < 0.05). The values did not vary by fetal presentation, mode or duration of delivery. Neonatal outcome was comparable between both study groups. CONCLUSION: In post-term gestation after 289 days nucleated red blood cells in cord blood are significantly increased. These results point towards a different fetal oxygenation in post-term pregnancies beyond 289 days of gestation and support the current practice of very close testing of fetal well-being under those circumstances.     

Nucleated red blood cells in concordant, appropriate-for-gestational age twins

OBJECTIVES: The purpose of this study was to test the hypothesis that neonatal nucleated red blood cell (RBC) counts are elevated in nondiscordant twins compared with singletons. STUDY DESIGN: We compared absolute nucleated RBC counts taken after birth in 2 groups of term, appropriate-for-gestational age infants; 74 concordant twins, and 29 singleton control infants. We excluded infants with factors associated with a potential increase in absolute nucleated RBC counts. RESULTS: Birth weight and gestational age were significantly lower in twins than in singletons (P < .01). Hematocrit, absolute nucleated RBC count, and corrected lymphocyte counts were significantly higher in twins (P < .01). In multiple regression, the significantly higher absolute nucleated RBC count in twins remained significantly higher even after taking into account gestational age and Apgar scores. CONCLUSION: Concordant, appropriate-for-gestational age twins have increased nucleated RBCs at birth compared with singleton control infants.     

Prediction of perinatal asphyxia with nucleated red blood cells in cord blood of newborns.

OBJECTIVE: To determine normal level of nucleated red blood cells (NRBC) per 100 white blood cells (WBC) in cord blood of term non-asphyxiated newborns and to investigate variations in NRBC counts in perinatal asphyxia. METHODS: A total of 75 cases were studied. Levels of NRBC per 100 WBC in umbilical venous blood were compared between 26 asphyxiated newborns (group I) and 49 non-asphyxiated newborns (group II). Correlation with neonatal outcome was also evaluated. RESULTS: The mean (+/-S.D.) NRBC per 100 WBC level in umbilical blood of newborns in group I was 16.5+/-6.4, range 3-25; whereas that in group II was 8.6+/-7.01, range 1-26. This difference was statistically significant (P<0.001). A statistically significant negative correlation existed between NRBC level and markers of acute intrapartum asphyxia, Apgar score and umbilical arterial pH (r=-0.50, P<0.001 and r=-0.48, P<0.001, respectively). Positive correlation was demonstrated with evidence of chronic antepartum asphyxia, presence of pregnancy induced hypertension and intrauterine growth restriction (r=2.66, P=0.02). A high NRBC count in umbilical blood correlated with poor early neonatal outcome. CONCLUSIONS: The level of NRBC per 100 WBC correlates both with acute as well as chronic antepartum asphyxia. Further, it can be used as a reliable index of early neonatal outcome.     

Nucleated red blood cell and platelet counts in asphyxiated neonates sufficient to result in permanent neurologic impairment

Objective.?Recent research has suggested that a nucleated red blood cell (NRBC) count ≥26 per 100 white blood cells (%) or the development of a platelet count ≤100 000 per mm³ within five days of birth is characteristic of neonates who have experienced acute birth asphyxia.

Study design.?Study cases were from the population defined in a prior publication (Prenat Neonat Med 1997;2:286). The impaired neonates were separated into three groups: group 1, persistent non-reactive fetal heart rate (FHR) pattern from admission until delivery; group 2, reactive FHR pattern on admission followed by a tachycardia, non-reactivity, repetitive variable or late decelerations, and usually a loss of variability; group 3, cases with a reactive FHR pattern on admission followed by a sudden, rapid and sustained deterioration of the FHR usually in response to a hypoxic sentinel event that lasted until delivery or a bradycardia on admission. The FHR pattern in group 3 is considered most consistent with acute birth asphyxia. We then examined these FHR groups with respect to the presence of hematologic injury. Chi-square testing was used to describe differences among the study populations.

Results.?Of the original 52 cases, sufficient hematologic data were available for 47. Of these, the proportion of cases with NRBC ≥26% was: group 1, 10/21 (47.6%); group 2, 0/14 (0%); group 3, 0/12 (0%). Those with a platelet count ≤100 000 per mm³: group 1, 11/21 (52.4%); group 2, 2/14 (14.3%); group 3, 0/12 (0%). Group 1 was significantly more likely to have an NRBC count ≥26% than group 3 (p = 0.0135). A platelet count ≤100 000 per mm³ within five days of birth was also significantly more likely to be encountered in group 1 as compared with group 3 (p = 0.0072).

Conclusion.?In cases of acute birth asphyxia, hematologic injury was infrequently encountered. Our findings suggest that a neonatal NRBC count ≥26% and/or a platelet count ≤100 000 per mm³ within five days of birth is inconsistent with acute birth asphyxia.     

Nucleated red blood cells count as a prognostic biomarker in predicting the complications of asphyxia in neonates

Objective: Nucleated-red-blood-cells (NRBC) count in umbilical cord of newborns is been suggested as a sign of birth asphyxia. The present study was conducted to explore the value of NRBC count in prognosis of asphyxiated neonates.

Methods: Sixty-three neonates with asphyxia were followed up for two years. Maternal and neonatal information was recorded follow by clinical and laboratory evaluation. NRBC-level was determined per 100 white-blood-cells (WBC). After discharge, follow-up of asphyxiated infants was performed using Denver II test at 6, 12, 18 and 24 months. Neonates were divided into two groups, with favorable and unfavorable outcome based on developmental delay or death.

Results: We observed that NRBC count with more than 11 per 100 WBC, had sensitivity of 85% and specificity of 90% in predicting complications of asphyxia, while in absolute NRBC count with more than 1554, the sensitivity and specificity were 85% and of 87%, respectively. Combination of NRBC?+?HIE (hypoxic ischemic encephalopathy) grade had a high-predictive power for determining the prognosis of asphyxia in neonates.

Conclusion: We demonstrate that NRBC/100 WBC and absolute NRCB count can be used as prognostic marker for neonatal asphyxia, which in combination with the severity of asphyxia could indicate high infant mortality, and complications of asphyxia. Further studies in a larger and multi center setting trail are warranted to investigate the value of NRBC and HIE in asphyxiate term infants.     

Umbilical cord blood stem cells

The umbilical cord contains a rich source of haematopoietic stem cells that can be used to reconstitute the blood system and can easily be extracted and cryopreserved, thus allowing for the establishment of HLA-typed stem cell banks. Recently, it has been demonstrated that umbilical cord stem cells have the potential to give rise to non-haematopoietic cells, such as bone, neural and endothelial cells. It is not clear whether these multipotential cells are mesenchymal-like cells or blood cells. Currently, the number of these specialized cells capable of undergoing the differentiation process into non-haematopoietic cells is low and remains a block to the clinical development of umbilical cord stem cells for non-haematopoietic cell therapy. Further research will allow us to overcome these hurdles. This expanded potential for umbilical cord stem cells might replace embryonic stem cells and other fetal cells for some cell and tissue therapies.     

Effect of preeclampsia and intrauterine growth restriction on endothelial progenitor cells in human umbilical cord blood

Objectives: Endothelial progenitor cells (EPCs) might play important roles in vascular homeostasis. This study evaluated the influence of prematurity, preeclampsia (PE) and intrauterine growth restriction (IUGR) on the EPC population in human umbilical cord blood (CB). Methods: CB was obtained from 19 preterm and 27 term deliveries. Mononuclear cells were isolated by gradient centrifugation and subjected to flow cytometry to obtain percentages of CD45(d) CD34+, CD45(d) CD133+, CD 45(d) CD34+ CD133+, and CD45(d) CD34+ CD133+ VEGFR-2+ cells. Clinical data were obtained using chart review. Results: Percentages of EPCs were comparable between preterm and term cord blood. CD45(d) CD34+ CD133+ cells were significantly decreased in CB samples obtained from women with PE (n = 14) [0.01, (0.00–2.6), [median, (range)], as compared to those without PE (n = 32) [1.74 (0.00–3.1)] (p = 0.005). CD45(d) CD133+ CD34? cells were significantly increased in presence of PE [0.43, (0.06–1.38)], (p = 0.002). CD45(d) CD34+ CD133+ cells were significantly decreased in presence of IUGR, with no change in CD45(d) CD133+ CD34? cells. Differences in EPC types associated with PE and IUGR were present only in term CB. Conclusions: Exposure to PE and IUGR is associated with significant changes in EPC population. Future studies are needed to explore the clinical impact of observed changes.     

Nucleated red blood cells as a marker of acidemia in term neonates.

OBJECTIVES: Nucleated red blood cells are produced in increased numbers under hypoxic conditions. We sought to examine the relationship between nucleated red blood cell count in the circulations of term neonates and other possible markers of fetal hypoxia. STUDY DESIGN: We prospectively collected umbilical blood from all live-born neonates delivered at our institution. Arterial blood was analyzed for pH and blood gas values. Venous blood was analyzed for nucleated red blood cell count. We reviewed the medical records for maternal data and neonatal outcomes of gestations of >/=37 weeks' duration. RESULTS: We evaluated 1561 cases. The mean nucleated red blood cell count per 100 white blood cells was 9.2 +/- 18.1 (range, 0-327). Nucleated red blood cell counts were higher in infants with pH <7.20 (P =.001). Both patients with respiratory acidemia and patients with uncompensated metabolic acidemia had elevated nucleated red blood cell counts (P =.013 and P =.014, respectively). As umbilical artery pH and base excess decreased, nucleated red blood cells became more prevalent. Elevated nucleated red blood cell counts were associated with presence of meconium (P =. 020) and neonatal intensive care unit admission (P =.024). CONCLUSIONS: We found that nucleated red blood cell counts vary widely in the circulation of term neonates. Elevated nucleated red blood cell counts are associated with fetal acidemia, meconium, and neonatal intensive care unit admission.     

Fetal "nonreassuring status" is associated with elevation of nucleated red blood cell counts and interleukin-6

OBJECTIVE: Previous studies have established the association between fetal hypoxia and elevated nucleated red blood cells (NRBCs). Animal studies have demonstrated that a rise in plasma erythropoietin (EPO) is not detectable until 4 to 6 hours after the initiation of hypoxia. In contrast, interleukin-6 (IL-6) has the capacity to directly induce erythroid maturation. Therefore, we set forth to evaluate the role of EPO and IL-6 as potential mediators of elevated fetal NRBCs in response to acute hypoxia. STUDY DESIGN: Low-risk pregnancies with a normal fetal heart rate at admission to labor and delivery were eligible for participation. Deliveries for "nonreassuring fetal status" comprised the study group. All other deliveries served as controls. Umbilical cord blood was prospectively collected for blood gas analysis, NRBC counts, EPO, and IL-6. RESULTS: One hundred women participated in the study. Nonparametric univariate analysis demonstrated a significant association between elevated NRBC counts and Apgar scores, arterial cord blood pH, base excess, EPO, and IL-6 levels (all P values <.01). Stepwise regression analysis identified only pH, IL-6, and EPO as independent variables associated with elevated NRBC counts at birth (all P values <.0001 with R2 of 0.27, 0.42, and 0.46, respectively). A significant increase in NRBC counts was noted in study patients. IL-6 was significantly increased in study patients, whereas there was no difference in EPO between groups. CONCLUSION: The fact that NRBC counts were elevated in fetuses who were delivered for "nonreassuring fetal status" with EPO being normal and IL-6 being elevated implies that IL-6 may have a unique, short-term role in elevating fetal NRBC counts.     

Cord blood erythropoietin and cord blood nucleated red blood cells for prediction of adverse neonatal outcome associated with maternal obesity in term pregnancy: prospective cohort study

Objective: To determine the adverse pregnancy outcomes associated with maternal pre-pregnancy overweight and obesity and we measure cord blood erythropoietin and NRBC count as indices of hypoxia and predictors of neonatal outcome.

Study design: This prospective cohort study was done in Minia University Hospital, carried out from May 2015 to April 2016. Two hundred and seventy full-term neonates born to mothers of various body mass indices were included. Excluded were neonates with major factors known to be associated with a potential increase in fetal erythropoiesis. Pre-pregnancy maternal BMI was calculated from maternally reported weight and height. Cord blood erythropoietin and nucleated red blood cells were measured.

Results: There is a significant increase of various adverse pregnancy outcomes as cesarean section. Postpartum hemorrhage and macrosomia with the increase of maternal pre-pregnancy BMI. Significant positive correlations between cord blood erythropoietin and nucleated red blood cells with maternal BMI.

Conclusion: The increase in the maternal pre-pregnancy BMI is associated with poor pregnancy outcomes. Cord blood erythropoietin and nucleated red blood cells can predict the poor neonatal outcome.     

运用流式细胞技术分析孕妇外周血中胎儿有核红细胞的比例与孕周的关系

目的 :探讨母亲外周血中胎儿有核红细胞 (NRBCs)的比例与孕周的关系。方法 :对 6 1名孕龄为 11～ 34周、年龄为 2 1～ 35岁的妇女的外周血中的胎儿细胞进行分离纯化 ,采用荧光激活细胞分离技术 (FACS)分选表达转铁蛋白受体的阳性细胞 (CD71+细胞 )。将孕妇组、未孕组及新生儿脐血组进行对照。结果 :孕 11～ 34周的孕妇外周血中 CD71+细胞的比例为 (0 .35± 0 .2 5 )× 10 - 2 ,与未孕组及新生儿脐血组均有极显著性差异。CD71+细胞在外周血中的比例在孕 17～18周达峰值 ,分别为 (0 .6 4± 0 .2 5 )× 10 - 2和 (0 .5 4± 0 .35 )× 10 - 2。结论 :早、中、晚期孕妇外周血中存在胎儿有核红细胞。利用母血循环中的胎儿细胞进行产前诊断的最佳时间应在妊娠 17～ 18周     

Significance of assay of nucleated RBCs in umbilical cord blood in neonates with meconium-stained amniotic fluid

Background: Approximately 8–15% of all infants are born with evidence of meconium-stained amniotic fluid (MSAF). MSAF is a potentially serious sign of fetal compromise and may indicate fetal hypoxia

Objectives and aim of the work: The present study was designed to evaluate the relationship between meconium stained amniotic fluid and fetal nucleated red blood cell counts. As well, we aim to evaluate the relationship between the presence of meconium in amniotic fluid and Apgar scores in neonates.

Subjects and methods: A prospectively case-controlled study was performed on 40 women with clear amniotic fluid as control and 40 women with meconium-stained amniotic fluid as the study group. At delivery, 2?ml of umbilical cord blood was collected and analyzed for nucleated red blood cell (NRBC).

Results: The mean NRBC counts in meconium-stained amniotic fluid was significantly higher than the control group (18.35?±?7.7 and 9.6?±?4.96), respectively (p?p?Conclusion: Our results support previous studies which indicate the presence of meconium can be associated with chronic fetal hypoxia as demonstrated by elevated fetal NRBC levels.     

Decrease and dysfunction of endothelial progenitor cells in umbilical cord blood with maternal pre-eclampsia

BACKGROUND: The pre-eclampsia is characterized by placental defective angiogenesis and maternal vascular/endothelial dysfunction. Recently, the decrease and senescence of endothelial progenitor cells (EPC) has been observed in maternal circulation with pre-eclampsia. Given the essential involvement of EPC in neovascularization and reendothelialization, we investigate whether or not the depletion of EPC is existent in placental/fetal circulation with maternal pre-eclampsia. METHODS: Samples of venous cord blood were collected during the labor of preeclamptic mothers (n = 14) and normotensive controls (n = 10). Circulating EPC were enumerated as AC133+/KDR+ cells via fluorescence-activated cell sorting (FACS) analysis. Additionally, EPC were expanded in vitro and identified by DiI-acLDL uptake and lectin staining by direct fluorescent staining under a laser scanning confocal microscope. EPC proliferation, migration and vasculogenesis activities were determined by MTT, modified Boyden chamber assay and in vitro vasculogenensis assay. RESULT: The placental/fetal circulating EPC numbers were significantly decreased in the pre-eclampsia group compared with the control (median, 200; range, 100-440 cells/mL vs 390; 270-440 cells/mL, P < 0.001), and after in vitro cultivation the numbers of EPC also decreased in pre-eclampsia group (19.5; 5.0-32.0 vs 39.5; 31.2-52.0 EPC/x200 field; P < 0.001). Both circulating EPC and cultivated EPC were inversely correlated with cord blood level of soluble fms-like tyrosine kinase 1 (sFlt-1). In addition, the EPC from patients with pre-eclampsia were significantly impaired in their proliferation, migration and vasculogenesis capacities. CONCLUSION: The present study documented the decrease and dysfunction of placental/fetal circulating EPC in patients with pre-eclampsia. The alteration is probably associated with the increased sFlt-1 levels in the umbilical cord blood.     

Percentiles for gas values in human umbilical cord blood

The distribution of gas values of umbilical cord blood was studied in an university clinic population during a period of 3 yr. All patients in labor were guided by obstetrical personnel and continuous electronic fetal monitoring (CTG). Microblood analyses were performed on indication of the CTG. The tenth percentile for the total population for umbilical artery blood pH was 7.14 and base excess was -12.7 mmol/l. The tenth percentile for pH in umbilical venous blood was 7.23 and base excess was -10.2 mmol/l. Increase of acidemia was seen in the following order: optimal pregnancy and labor, spontaneous vertex delivery, multiparity, primiparity, instrumental and breech delivery. Percentiles of umbilical cord blood gases could serve as an index for the standard of obstetrical care in addition to perinatal mortality and other measures of perinatal morbidity.