Nucleated Red Blood Cell Counts Research Articles

Nucleated Red Blood Cells in Uncomplicated Prolonged Pregnancy

Elevated counts of nucleated red blood cells (NRBCs), as well as prolongation of pregnancy, have been suggested as predictors of adverse perinatal outcome. However, the association between these 2 variables has received only minimal attention. We sought to evaluate fetal NRBCs in prolonged pregnancies. Umbilical cord blood was prospectively collected at delivery from 75 prolonged (at or beyond 287 days) pregnancies. One hundred and fifty term deliveries (260-286 days) served as controls. All pregnancies were accurately dated with the use of first-trimester sonography. Fetal biophysical profile testing was initiated at 40 weeks of gestation. Patients were delivered if they were in spontaneous labor or the biophysical profile was nonreassuring or by 42 weeks of gestation. Nucleated red blood cell counts were expressed per 100 white blood cells (WBC). Umbilical artery pH studies, as well as other demographic and clinical variables, were obtained. Prolonged pregnancy was associated with a significantly increased incidence of induction of labor and a greater birth weight. There were no other differences between the study group and controls. The median NRBCs per 100 WBCs in prolonged pregnancy was not significantly elevated over the term values (median 3, range 0-35 versus median 3, range 0-34, respectively; P =.25). Neonatal outcome was also comparable between groups. The univariate regression analysis demonstrated a significant association between elevated NRBC counts and low arterial cord blood pH (P <.008, R = 0.175), elevated base excess (P =.02, R = 0.149), low platelet counts (P =.046, R = 0.134), and male gender (P =.028). Stepwise regression analysis revealed that low arterial cord blood pH and male gender were the only independent variables predicting elevated NRBC counts at birth. The findings of this study suggest that elevated NRBC counts are associated with specific pregnancy complications rather than uncomplicated prolonged pregnancies in general.

Workflow improvement and impact of the new Beckman Coulter LH 1500 high throughput automated hematology workcell.

Our core laboratory at St. Joseph's Medical Center (SJMC) recently installed the new Beckman Coulter LH 1500 fully automated hematology workcell. Like many laboratories in North America and other parts of the world, we are under significant pressure to improve productivity, reduce costs, and improve service provision to our hospital and clinician bases. The difficulty of meeting this challenge is often further compounded by an increasing shortage of qualified technologist personnel. We recently reported on the significant productivity gains with the introduction of the LH 750 hematology system into the core laboratory, including a 23% reduction in slide review rate, automation of reticulocyte and nucleated red blood cell counts, and an 82% increase in the pass-through rate. Evolution to the next stage of automation has come much quicker than anticipated owing to a steep rise in workload and an ever increasing shortage of trained and experienced technologists to fill vacancies in the 24-hour core laboratory operation. We chose to upgrade our LH 750 analyzers to the newly introduced LH 1500 hematology workcell in order to cope with the increased workload and shortage of available experienced hematology technologists. The LH 1500 is a compact, high throughput, fully automated hematology workcell. It is designed to automate all manual process and handling steps associated with hematology analyses, including sample sorting, loading and unloading of cassettes, automatic rerun and reflex testing, sample storage, and tracking of samples. The LH 1500 is comprised of a minimum of 2, and up to 4, LH 750 instruments (with or without integrated slidemaker/stainers). The instruments are bidirectionally interfaced and linked to a fully automated conveyor track, specimen inlet and outlet stations, a sample stockyard, and a line controller. The configuration we chose at SJMC incorporates 1 LH 750 and 1 LH 755. We report that the upgrade to the LH 1500 was a relatively straightforward process and required no redesign of the core laboratory. Based on our evaluation, we estimate cost savings with the LH 1500 of between three quarters to 1 full-time equivalent, which eliminated or decreased many manual handling steps. In addition, this increase in efficiency has freed up our technologist resources to concentrate on the more difficult and clinically important samples. This is the first published report on the new LH 1500 hematology workcell. Our research indicates that the LH 1500 is the first hematology workcell to offer hematology laboratories the next level of automation and virtually eliminate preanalytical and postanalytical sample handling and sorting. For core laboratories and high-throughput hematology laboratories that face similar pressures to ours, the LH 1500 would appear as an attractive solution to maximize hematology productivity and improve service delivery.

Timing of Fetal Nucleated Red Blood Cell Count Elevation in Response to Acute Hypoxia

We determined the effect of an acute episode of severe hypoxia on peripheral nucleated red blood cell (RBC) counts in the fetal rat. Timed pregnant rats were randomized to a 2-hour exposure to hypoxia (placement in a chamber containing a gas mixture with 9% O₂ +3% CO₂+ balanced N₂) or to a 2-hour exposure to a sham chamber containing room air. Two maternal animals per group underwent cesarean section immediately after the 2-hour period and then 4, 12, 24, 36, 48, and 60 h after exposure. Fetal nucleated RBC counts were compared between groups at each time interval. The nucleated RBC counts were not significantly different in the hypoxia group until 12 h (mean ± SEM 158.0 ± 22.4 RBC/10 high-power fields vs. 90.6 ± 11.0; p = 0.03) and 24 h (133.2 ± 16.0 vs. 84.1 ± 9.0; p = 0.04) after exposure. There were no differences between groups 36, 48, and 60 h after exposure. In the near-term rat fetus, acute hypoxia was associated with a delayed but transient increase in peripheral nucleated RBC counts.

Are elevated fetal nucleated red blood cell counts an indirect reflection of enhanced erythropoietin activity?

Objective Animal and human studies demonstrated elevated erythropoietin (EPO) levels in response to intrauterine hypoxic events. Other studies documented an association between fetal hypoxia and elevated nucleated red blood cell (NRBC) counts and have speculated that it is the elevation of EPO that results in an increase in NRBC counts. Thus, the purpose of our study was to determine the correlation between EPO levels and NRBC counts in the human fetus. Study design Data were collected prospectively between April and July of 2003. Term singleton pregnancies were eligible to participate in the study. Umbilical cord blood was collected immediately after birth for determination of fetal EPO levels and NRBC counts. Results Forty pregnancies formed the study population. The mean gestational age at delivery was 39.5 ± 1.2 weeks (±SD) and the mean birth weight was 3500 ± 372 g. The median EPO (mU/mL) was 34 (range 13-427). The median NRBC/100 white blood cells was 10 (range 0-150). A simple regression analysis indicated that NRBC counts are significantly and positively correlated with EPO (P = .0004, R2 = 0.287). Conclusion Our results suggest a significant association between EPO and NRBC counts in term singleton fetuses. These results support the hypothesis that fetal NRBC and EPO are interrelated. However, the relatively low R2 indicates that there are other (yet to be determined) hypoxia-derived mediators that result in an elevation of fetal NRBC counts.

Are elevated fetal nucleated red blood cell counts an indirect reflection of enhanced erythropoietin activity?

Objective Animal and human studies demonstrated elevated erythropoietin (EPO) levels in response to intrauterine hypoxic events. Other studies documented an association between fetal hypoxia and elevated nucleated red blood cell (NRBC) counts and have speculated that it is the elevation of EPO that results in an increase in NRBC counts. Thus, the purpose of our study was to determine the correlation between EPO levels and NRBC counts in the human fetus. Study design Data were collected prospectively between April and July of 2003. Term singleton pregnancies were eligible to participate in the study. Umbilical cord blood was collected immediately after birth for determination of fetal EPO levels and NRBC counts. Results Forty pregnancies formed the study population. The mean gestational age at delivery was 39.5 ± 1.2 weeks (±SD) and the mean birth weight was 3500 ± 372 g. The median EPO (mU/mL) was 34 (range 13-427). The median NRBC/100 white blood cells was 10 (range 0-150). A simple regression analysis indicated that NRBC counts are significantly and positively correlated with EPO ( P = .0004, R 2 = 0.287). Conclusion Our results suggest a significant association between EPO and NRBC counts in term singleton fetuses. These results support the hypothesis that fetal NRBC and EPO are interrelated. However, the relatively low R 2 indicates that there are other (yet to be determined) hypoxia-derived mediators that result in an elevation of fetal NRBC counts.

Nucleated red blood cells in preterm infants who have necrotizing enterocolitis

Absolute nucleated red blood cell counts for 23 preterm newborn infants who subsequently had development of necrotizing enterocolitis were significantly higher than for 23 control infants. These infants may have been exposed to relative intrauterine hypoxemia, a possible risk factor for the development of necrotizing enterocolitis.

Nucleated red blood cells in preterm infants who have necrotizing enterocolitis

Absolute nucleated red blood cell counts for 23 preterm newborn infants who subsequently had development of necrotizing enterocolitis were significantly higher than for 23 control infants. These infants may have been exposed to relative intrauterine hypoxemia, a possible risk factor for the development of necrotizing enterocolitis.

Fetal scalp nucleated red blood cell counts in pregnancies with meconium stained amniotic fluid

CIES WITH MECONIUM STAINED AMNIOTIC FLUID ASAF FERBER, EBRAHIM SHAHIM, ALINA WEISSMANN-BRENNER, MICHAEL DIVON, Lenox Hill Hospital, OB/GYN, New York, NY OBJECTIVE: The clinical significance of meconium stained amniotic fluid (MEC) is still debated. Recent studies suggested that nucleated red blood cell (NRBC) counts are elevated in neonates with meconium aspiration syndrome. Thus, we sought to determine the correlation between intrapartum NRBC counts, pH values and MEC. STUDY DESIGN: Fetal scalp capillary blood specimens were prospectively collected in laboring patients who underwent scalp sampling. Specimens were evaluated for pH and NRBC counts. The presence and quality of meconium in the amniotic fluid were noted. Statistical analysis included Student’s t-test and simple regression. RESULTS: 78 term, singleton pregnancies formed the study population. The mean gestational age was 39.7 ± 1.2 ( ± S.D.) weeks. The mean birth weight was 3493 ± 451 grams. Themean scalp pHwas 7.26 ± 0.05 and themean NRBC per 100 WBC was 8.8 ± 8.3. Simple regression analysis revealed no significant correlation between fetal scalp pH and NRBC values (P = 0.94). 17 patients had MEC. Scalp pH values in patients with and without MEC were 7.25 ± 0.06 and 7.26 ± 0.05, respectively, P = 0.64. However, the NRBC counts in fetuses with MEC were significantly elevated (11.4 ± 10.6 vs. 7.4 ± 6.4, respectively, P = 0.031). Patients were further divided into clear fluid/thin MEC vs. moderate/thick MEC. There were no scalp pH differences between groups (7.24 ± 0.07 vs. 7.26 ± 0.05, respectively, P = 0.27). However, the NRBC counts in the moderate/thick MEC group were significantly different (14.0 ± 13.1 vs. 7.6 ± 6.2, respectively, P = 0.003). CONCLUSION: Previous studies have established an association between NRBC counts and perinatal outcome. Our results indicate that fetal NRBC counts are elevated in patients withmoderate/thick MEC. No such difference in pH values was noted. We speculate that scalp NRBC counts have the potential to either predict neonatal meconium aspiration syndrome or identify pregnancies that may benefit from immediate treatment.

Activin a plasma levels at birth: an index of fetal hypoxia in preterm newborn.

Activin-A is a growth factor involved in cell growth and differentiation, neuronal survival, early embryonic development and erythropoiesis. Hypoxemia is a specific trigger for increasing activin-A in fetal lamb circulation. We tested the hypothesis that fetal hypoxia induces activin-A secretion in preterm newborn infants. Fifty newborn infants with gestational ages ranging from 26 to 36 wk were enrolled in a prospective study performed at the Pediatrics, Obstetrics and Reproductive Medicine Department, University of Siena, Italy. Heparinized blood samples were obtained from the umbilical vein after cord clamping, immediately after delivery. Activin A, hypoxanthine (Hx), xanthine (Xa) plasma levels and absolute nucleated red blood cell (NRBC) count were measured. Activin-A levels (p < 0.0001) and NRBC (p < 0.0001) were significantly higher in hypoxic than in non hypoxic preterm newborns. Cord activin A levels were significantly related with Hx (taua=0.64, taub=0.64, p < 0.0001) and Xa (taua=0.56, taub=0.57, p < 0.0001) levels, NRBC ((taua=-0.45, taub=-0.46, p < 0.0001) count; pH (taua=-0.47, taub=-0.48, p < 0.0001) and base deficit (taua=-0.36, taub=0.-0.36, p = 0.0002). Preterm newborns with signs of perinatal hypoxia at birth have increased activin-A levels, suggesting that activin-A may reflect indirectly intrauterine hypoxia.

Fine-needle aspiration in the evaluation of nucleated red blood cells in the human placenta

Objective: The purpose of this study was to evaluate the correlation between placental and umbilical cord nucleated red blood cell counts. Study Design: Eighty placentas and their matched umbilical cord blood samples were collected prospectively immediately after delivery. In vitro fine-needle aspiration biopsy specimens were used to obtain placental tissue samples. Nucleated red blood cells were counted by both manual microscopy and flow cytometry. Statistical analysis included Wilcoxon signed rank test and Spearman correlation. Results: The median nucleated red blood cell counts/100 white blood cell counts for manual microscopy in umbilical cord blood; placental samples were 7.5 and 3.0, respectively (P <.0001). The median nucleated red blood cell counts for flow cytometric determination in umbilical cord blood and placental samples were 11.3 and 8.6, respectively (P <.0001). The Spearman correlation between manually counted umbilical cord blood samples and the placental tissue specimens was 0.66 (P <.0001). The Spearman correlation between flow cytometrically counted umbilical cord blood nucleated red blood cell and nucleated red blood cell counts that were obtained from the placenta was statistically significant (r = 0.74, P <.0001). The Spearman correlation between manual microscopy and flow cytometry for umbilical cord samples and their matched placental tissue specimens were 0.80 and 0.58, respectively, with all probability values at <.0001. Conclusion: Previous studies have reported an association between acute and chronic hypoxia and elevated nucleated red blood cells. Our results indicate that in vitro placental nucleated red blood cell counts correlate with umbilical cord nucleated red blood cell counts and suggest that antenatal evaluation of fetal nucleated red blood cells could be achieved by placental fine-needle aspiration biopsy. (Am J Obstet Gynecol 2003;189:155-8.)

Nucleated red blood cell counts: not associated with brain injury or outcome

The objective was to determine whether an elevated nucleated red blood cell count at birth after perinatal depression is associated with brain injury as measured by (1) proton magnetic resonance spectroscopy and (2) abnormal neurodevelopmental outcome at 30 months of age. The nucleated red blood cell counts from the first 24 hours of life were statistically analyzed in 33 term infants enrolled in a prospective study of the value of magnetic resonance imaging for the determination of neurodevelopmental outcome after perinatal depression. Nucleated red blood cell counts were elevated in 13/33 (39%). Abnormal outcome (19/33, 54%) was associated with Score for Neonatal Acute Physiology-Perinatal Extension ( P = 0.04), decreased N-acetylaspartate to choline ratio in the basal ganglia ( P = 0.009), and increased lactate to choline ratio in the basal ganglia ( P = 0.02), but not with cord pH, Apgar score, or nucleated red blood cell value. In a logistic regression model, increasing nucleated red blood cell counts did not increase the odds of an abnormal outcome at 30 months of age (OR 1.02, P = 0.17). In a population of neonates with perinatal depression, the nucleated red blood cell count at birth does not correlate with magnetic resonance spectroscopy or 30-month neurodevelopmental outcome. The nucleated red blood cell count should not be used as a surrogate marker for subsequent brain injury.

The association of fetal heart rate patterns with nucleated red blood cell counts at birth

Objective: The purpose of this study was to evaluate the relationship between fetal heart rate patterns and fetal nucleated red blood cell counts. Study Design: Data were collected prospectively from March through September 2000. Umbilical cord blood was used for nucleated red blood cell analysis. The fetal heart rate pattern was analyzed for reactivity; presence, duration, and type of decelerations; and time interval between the last acceleration and delivery. Results: Two hundred seventy-nine singleton term pregnancies formed the study population, 67% of which were delivered vaginally. The median nucleated red blood cells per 100 white blood cells was 7 (range, 0-158). The univariate analysis indicated that nucleated red blood cells are correlated significantly with abnormal fetal heart rate patterns, time interval between the last acceleration and delivery, fetal growth restriction, the presence of meconium, and a 1-minute Apgar score of ≤7. However, the stepwise regression analysis identified the time interval between the last acceleration and delivery as the only variable that independently predicted elevated nucleated red blood cell count at birth (P <.0001, R2 = 0.26). Conclusion: Earlier studies have demonstrated an association between adverse perinatal outcome and elevated nucleated red blood cell count. In view of the high false-positive rate that is associated with the prediction of adverse perinatal outcome by fetal heart rate abnormalities, our results support previous studies that indicate that the presence of fetal heart rate accelerations is a reliable predictor of the nonhypoxic fetus. (Am J Obstet Gynecol 2003;188:1228-30.)

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 cells in infants of mothers with asthma

Objective: The purpose of this study was to evaluate whether the absolute nucleated red blood cell and lymphocyte count is elevated in term, appropriate-for-gestational-age infants born to women with asthma. Study design: We compared absolute nucleated red blood cell counts taken during the first 12 hours of life in two groups of term, vaginally delivered, appropriate-for-gestational-age infants; one group was born to mothers with active asthma during pregnancy (n = 28 infants), and the other group was born to control mothers (n = 29 infants). Asthma severity was classified according to the National Asthma Education and Prevention Program. We excluded infants of women with diabetes mellitus, hypertension, alcohol, and tobacco or drug abuse and infants with fetal heart rate abnormalities, hemolysis, blood loss, or chromosomal anomalies. Results: There were no differences between groups in birth weight, gestational age, maternal age, gravidity, parity, maternal analgesia during labor, 1- and 5-minute Apgar scores, and infant sex. The hematocrit level, red blood cell count, absolute nucleated red blood cell count, and corrected leukocyte and lymphocyte counts were significantly higher in the asthma group than in the control group. The platelet count was not significantly different between groups. The absolute nucleated red blood cell count correlated significantly with the asthma severity score (r2 = 28%, P < .001). Backward stepwise multiple regression that included Apgar scores and gestational age showed a significant correlation of absolute nucleated red blood cell count with the presence of asthma and its severity (P < .001). Conclusion: At birth, term appropriate-for-gestational-age infants born to mothers with asthma have increased circulating absolute nucleated red blood cell and lymphocyte counts compared with control infants. (Am J Obstet Gynecol 2003;188:409-12.)

Labor Does Not Affect the Neonatal Absolute Nucleated Red Blood Cell Count

We investigated whether the presence or absence of physiologic labor may affect the neonatal nucleated red blood cell (RBC) count. We compared absolute nucleated RBC counts taken at approximately 6 hours of life in term infants born by elective cesarean delivery without trial of labor ( n = 32) and in vaginally delivered infants ( n = 28). Venous blood samples were analyzed and differential cell counts were performed manually; absolute nucleated RBC were counted and expressed as an absolute number. There were no significant differences between groups in birth weight, gestational age, maternal age, gravidity, parity, maternal analgesia during labor, 1- and 5-minute Apgar scores, and infant sex. There was a significantly higher hematocrit and RBC count in the vaginally delivered group as compared with the cesarean group. The absolute nucleated RBC, corrected leukocyte and lymphocyte, and platelet counts were strikingly similar in both groups. We conclude that labor does not affect the neonatal nucleated RBC count. This finding supports the speculation that physiologic labor does not induce a fetal hypoxemia severe or prolonged enough to produce hematological evidence of increased erythropoiesis.

Nucleated red blood cells in polycythemic infants

Objective: This study was undertaken to evaluate whether the absolute nucleated red blood cell (RBC) count is elevated in term, appropriate-for-gestational-age (AGA) polycythemic infants. Study Design: We compared absolute nucleated RBC counts taken during the first 12 hours of life in term, AGA infants with neonatal polycythemia (n = 29), and in control, nonpolycythemic infants (n = 37). We excluded infants of women with diabetes, hypertension, and alcohol, tobacco, or drug abuse, and those with fetal heart rate abnormalities or low Apgar scores, hemolysis, blood loss, or chromosomal anomalies. Results: There were no differences between groups in birth weight, gestational age, or other demographic or perinatal factors. The hematocrit, RBC count, and absolute nucleated RBC counts were significantly higher and the platelet counts significantly lower in the polycythemic group. Regression analysis that included Apgar scores and gestational age showed a significant correlation of absolute nucleated RBC count with the polycythemia status only (P = .017). Conclusion: At birth, term AGA polycythemic infants have increased indices of active erythropoiesis. We speculate that this finding is suggestive of subtle fetal hypoxemia. (Am J Obstet Gynecol 2003;188:193–5.)

Flow cytometric-based isolation of nucleated erythroid cells during maturation: an approach to cell surface antigen studies.

Nucleated red blood cells (NRBCs) are involved in normal physiologic processes, as well as in several malignancies. They are usually counted manually under the microscope. However, blood sample manipulation may be a source of variability and manual counting is imprecise, time-consuming, and subjective. To improve identification of CD45-negative cells, we used a flow cytometry technique that avoids the addition of lysing reagents and stains viable cell nuclei. We applied this method for counting and isolating NRBC subpopulations in whole blood samples, using DNA/RNA viable staining to discriminate nonnucleated erythroid cells and debris. NRBC counts gave 197.95 cells per mm(3) in mobilized peripheral blood samples (1.00%, n = 20), 3897.59 cells per mm(3) in leukapheresis products (3.08%, n = 20), and 765.21 cells per mm(3) in cord blood samples (6.09%, n = 20). Normal bone marrow counts were 5449.42 cells per mm(3) (11.76%, n = 20). Scatter profiles showed three distinct populations, from early to late-stage erythroblasts, consisting of erythroblasts, orthochromatic erythroblasts, and ejected nuclei, as confirmed by Wright-Giemsa staining. In addition, flow cytometry immunophenotyping showed that glycophorin A was expressed dimly on NRBCs during maturation. These findings point to the feasibility of live NRBCs studies, which offer great potential for a wide range of disciplines.

Nucleated red blood cell counts and erythropoietin levels in high-risk neonates.

The presence of increased numbers of nucleated red blood cells (NRBC) and increased levels of erythropoietin (EPO) in the circulation of neonates has been associated with states of relative hypoxia. The aim of this study is to assess the pattern of NRBC counts and EPO levels in a group of high-risk neonates under stress conditions and determine the short-term outcome for these babies by using these parameters. There were 69 high-risk neonates; 14 intrauterine growth retarded (IUGR), 25 preterm infants, 18 term infants with asphyxia and 12 infants of diabetic mothers. Control groups included healthy, term infants delivered either vaginally (n = 18) or with cesarean section (n = 19). Three blood samples were obtained from each infant within 12 h (initial), 3 days and 7 days after birth to measure NRBC counts and EPO levels. Neonatal and short-term outcomes at 3 and 6 months of age were determined. There was no significant difference among the groups with regard to the initial serum EPO concentrations. The initial NRBC counts were significantly lower in the control groups compared with the study groups (P = 0.002). While there was no significant difference between patients with good and poor outcome in terms of EPO concentrations of initial samples, a significant difference existed in terms of NRBC counts (P = 0.038). Both serum EPO level and NRBC count provide limited clinical benefit in the detection of pathological conditions of the neonatal period, but NRBC count determination seems to be especially helpful in predicting short-term neurodevelopmental outcome.

The feasibility of using histologic placental sections to predict newborn nucleated red blood cell counts

OBJECTIVE:To determine the feasibility of using calculated nucleated red blood cell (RBC) counts from histologic placental slides to predict newborn nucleated RBC counts.METHODS:This retrospective study compared absolute nucleated RBC counts from 24 newborns, diagnosed with fetal distress in labor, with counts calculated from their histologic placental slides. A simple linear regression model was tested with newborn nucleated RBC counts as the dependent variable and calculated placental nucleated RBC counts as the independent variable.RESULTS:The mean ± standard deviation newborn nucleated RBC count was 4.81 × 109 ± 5.46 × 109/L compared with 1.37 × 109 ± 1.78 × 109/L calculated from placental sections. These data were normalized by logarithmic transformation. A significant linear regression was obtained, r2 = 0.74, P < .001. The prediction equation obtained was natural logarithm (newborn nucleated RBC count) is equal to 1.002 × natural logarithm (placental nucleated RBC count) + 1.173.CONCLUSION:It is feasible to calculate nucleated RBC counts from histologic slides of the placenta that are predictive of newborn nucleated RBC counts. Further work on more homogeneous groups of subjects is necessary to increase the precision of the method. The placenta could serve as a surrogate source for newborn whole blood nucleated RBC counts around the time of birth.

The Feasibility of Using Histologic Placental Sections to Predict Newborn Nucleated Red Blood Cell Counts

In Brief OBJECTIVE To determine the feasibility of using calculated nucleated red blood cell (RBC) counts from histologic placental slides to predict newborn nucleated RBC counts. METHODS This retrospective study compared absolute nucleated RBC counts from 24 newborns, diagnosed with fetal distress in labor, with counts calculated from their histologic placental slides. A simple linear regression model was tested with newborn nucleated RBC counts as the dependent variable and calculated placental nucleated RBC counts as the independent variable. RESULTS The mean ± standard deviation newborn nucleated RBC count was 4.81 × 109 ± 5.46 × 109/L compared with 1.37 × 109 ± 1.78 × 109/L calculated from placental sections. These data were normalized by logarithmic transformation. A significant linear regression was obtained, r2 = 0.74, P < .001. The prediction equation obtained was natural logarithm (newborn nucleated RBC count) is equal to 1.002 × natural logarithm (placental nucleated RBC count) + 1.173. CONCLUSION It is feasible to calculate nucleated RBC counts from histologic slides of the placenta that are predictive of newborn nucleated RBC counts. Further work on more homogeneous groups of subjects is necessary to increase the precision of the method. The placenta could serve as a surrogate source for newborn whole blood nucleated RBC counts around the time of birth. Nucleated red blood cell counts from placental sections reflect newborn counts shortly after birth.