Nucleated red blood cell counts in term neonates with umbilical artery pH < or = 7.00

The purpose of this study was to determine whether nucleated red blood cell (NRBC) counts are elevated in term neonates who have severe fetal acidemia at birth. The neonatal NRBC counts of term (gestational age > or = 37 weeks) neonates with pathological acidemia were compared with those from control neonates who met the following criteria: gestational age > or = 37 weeks, birth weight > or = 2800 g, umbilical artery pH > or = 7.25, and a 5-minute APGAR > 7. Pathological acidemia was defined as an umbilical artery pH < or = 7.0 and a base excess > -12 mEq/L. Twenty-six neonates met all inclusion criteria and were compared to 78 controls. The mean NRBC/100 WBC was 11.9 +/- 13.5 (range 0 to 45) for acidemic neonates compared to 3.9 +/- 2.9 NRBC/100 WBC (range 0 to 11) for control neonates [p <0.001]. Our findings suggest that the onset of hypoxia-ischemia in pregnancies complicated by severe fetal acidemia often begins prior to the intrapartum period.     

Nucleated red blood cell count in the differentiation of fetuses with pathologic growth restriction from healthy small-for-gestational-age fetuses

OBJECTIVE: The purpose of this study was to evaluate the utility of the neonatal nucleated red blood cell count in differentiating the fetus with growth restriction from the small but otherwise healthy fetus. STUDY DESIGN: Perinatal outcomes were evaluated prospectively for all neonates admitted to the neonatal intensive care unit in 1997. Nonanomalous neonates with normal phenotype and a complete blood cell count performed within the first 6 hours after birth were included in the study. All neonates with birth weights lower than the 10th percentile for gestational age were considered small for gestational age. Neonates were divided into four groups: small-for-gestational-age neonates with elevated nucleated red blood cell counts, appropriately grown neonates with elevated nucleated red blood cell counts, small-for-gestational-age neonates with normal nucleated red blood cell counts, and appropriately grown neonates with normal nucleated red blood cell counts. Analysis of variance, chi(2) tests, and stepwise regression were used for statistical analysis. RESULTS: Two hundred thirty-seven neonates met the inclusion criteria. Forty-three were small for gestational age. Small-for-gestational-age neonates with high nucleated red blood cell counts had significantly lower umbilical artery pH and were more likely to require mechanical ventilation or blood pressure support agents. Subgroup analysis demonstrated that small-for-gestational-age neonates with elevated nucleated red blood cell counts had significantly more adverse outcomes than did small-for-gestational-age neonates with normal nucleated red blood cell counts. Outcomes of small-for-gestational-age neonates with normal nucleated red blood cell counts were essentially identical to those of appropriately grown neonates. CONCLUSION: An elevated nucleated red blood cell count may distinguish the fetus with growth restriction from the small but healthy fetus.     

Association of ABO incompatibility with elevation of nucleated red blood cell counts in term neonates

OBJECTIVE: Nucleated red blood cells in the circulation in term neonates have been associated with a wide range of pathologic conditions. We sought to examine the relationship between nucleated red blood cells in the circulation of term neonates and maternal-neonatal blood type compatibility. STUDY DESIGN: We prospectively collected umbilical blood from all live-born neonates delivered at our institution. Venous blood was analyzed for nucleated red blood cells and is reported as the number of nucleated red blood cells per 100 white blood cells. We reviewed maternal and neonatal records for neonates born at > or =37 weeks' gestation for correlative clinical data. Statistical analysis was performed with the SAS statistical software package (version 6.12; SAS Institute, Inc, Cary, NC). Kruskal-Wallis analysis was used as a nonparametric test. RESULTS: We evaluated 1661 neonates delivered during the study period and found a mean (+/-SD) of 9.29 +/- 18.56 nucleated red blood cells per 100 white blood cells (range, 0-327 nucleated red blood cells per 100 white blood cells). Nucleated red blood cell counts were lower in ABO-compatible maternal-fetal dyads (mean +/- SD, 8.29 +/- 12.84 nucleated red blood cells per 100 white blood cells; range, 0-216 nucleated red blood cells per 100 white blood cells) than in ABO-incompatible dyads (mean +/- SD, 13.16 +/- 13.16 nucleated red blood cells per 100 white blood cells; range, 0-327 nucleated red blood cells/100 white blood cells; P =.006). Neonates of mothers with blood groups A and B had significantly lower nucleated red blood cell counts (P <.05). Dyads with maternal type O and neonate type B had significantly higher nucleated red blood cell counts (P <.002). Nonparametric testing determined that type O mother and type B neonate combinations had significantly higher umbilical cord nucleated red blood cell counts (P <.001). CONCLUSION: Maternal-fetal ABO incompatibility is associated with elevation of nucleated red blood cell count in term neonates. Nucleated red blood cell elevation does not always connote a serious pathologic process, however, because ABO incompatibility usually does not adversely affect neonatal outcome. The clinical significance of an elevated nucleated red blood cell count thus is limited.     

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.     

Significance of high and normal neonatal nucleated red blood cell count in small-for-gestational-age newborns

The objective of this study was to evaluate the obstetrical and neonatal outcome in small-for-gestational age (SGA) and appropriate-for-gestational-age (AGA) fetuses with normal and elevated neonatal nucleated red blood cell counts. Therefore the nucleated red blood cell count was assessed immediately after birth in 906 neonates delivered at our institution and the perinatal and neonatal data were compared. Postnatally, infants were classified as SGA if they had a birth weight for given gestational age below the 10th percentile. Neonates were allocated to four groups according to their nucleated red blood cell count: SGA neonates with normal and high nucleated red blood cell count and appropriate-for-gestational-age newborns (AGA) with normal and high nucleated red blood cell count. Statistical analysis included the Mann-Whitney U-Test, Student's t-test, chi2 analysis of variance and stepwise regression analysis. SGA newborns with high nucleated red blood cell count had a significantly lower birth weight, a lower gestational age at delivery, lower arterial and venous pH values, lower Apgar scores at 1 min, 5 min and 10 min as well as lower base excess values compared to the other groups. They had to be transferred significantly more often and stayed longer in the neonatal intensive care unit. Three cases of intraventricular hemorrhage, four cases of necrotizing enterocolotis and two neonatal deaths occurred all in the SGA group with high neonatal nucleated red blood cell counts. Neonatal outcomes of SGA and AGA newborns with normal nucleated red blood cell counts were comparable. Our data do therefore underline the possible value of neonatal nucleated red blood cell counts to differentiate the healthy small-for-gestational age newborn from the truely growth retarded newborn.     

Neonatal nucleated red blood cells and the prediction of cerebral white matter injury in preterm infants

OBJECTIVE: To estimate whether neonates with cerebral white matter injury have significant elevations in nucleated red blood cell counts and to estimate their predictive ability in identifying injury. METHODS: This case-control study identified 176 infants born at 23-34 weeks of gestation between November 1994 and October 2004 at a single university hospital and with cerebral white matter injury characterized by periventricular leukomalacia (PVL) or ventriculomegaly due to white matter atrophy. A control was matched to each case using the subsequent delivery within 7 days of that gestational age without brain injury. RESULTS: The gestational age at birth was 27 weeks for both groups, but the cases had a significantly lower birth weight (mean +/- standard deviation: 958 +/- 306 g compared with 1,038 +/- 381 g, P = .001). There was no difference in cesarean delivery (48% cases compared with 44% controls, P = .59). The cases had a significant increase in nucleated red blood cells per 100 white blood cells (WBC) (median, 5th percentile and 95th percentile: 22, 3 and 374 cases compared with 14, 1 and 312 controls; P = .02). Markers of chronic hypoxia, such as intrauterine growth restriction and oligohydramnios, and markers of acute hypoxia, such as an umbilical arterial pH less than 7.0 or base excess less than -12 mM, were both associated with significantly elevated neonatal nucleated red blood cell counts. A neonatal nucleated red blood cell count of 18 per 100 WBCs had a sensitivity of 56.9%, specificity of 57.9%, positive predictive value of 57.9%, and negative predictive value of 56.9% in predicting the development of cerebral white matter injury in this matched case-control sample. CONCLUSION: Preterm neonates with cerebral white matter injury have significant increases in nucleated red blood cell counts. Both acute and chronic hypoxia-ischemia can increase these counts, which limits their usefulness in timing injury. The predictive value of nucleated red blood cell counts at birth in identifying injury is poor. LEVEL OF EVIDENCE: II-2.     

Neonatal Nucleated Red Blood Cell and Lymphocyte Counts in Fetal Brain Injury

Objective: To determine whether neonatal lymphocyte or nucleated red blood cell (RBC) counts can be used to date fetal neurologic injury.Methods: Singleton, term infants with hypoxic-ischemic encephalopathy, permanent neurologic impairment, and sufficient laboratory data were divided into two groups: infants with preadmission injury, manifested by a nonreactive fetal heart rate (FHR) pattern from admission until delivery; and infants with acute injury, manifested by a normal FHR pattern followed by a sudden prolonged FHR deceleration. Lymphocyte and nucleated RBC values were compared with published high normal counts for normal neonates: 8000 lymphocytes/mm³ and 2000 nucleated RBCs/mm³.Results: The study population consisted of 101 neonates. In the first hours of life, lymphocyte counts were elevated among injured newborns, and then the counts rapidly normalized. Brain-injured neonates were 25 times more likely to have a lymphocyte count greater than 8000 than were normal neonates (54 [62%] of 87 versus 6 [7%] of 84; odds ratio 25.5; 95% confidence interval 8.8, 80.1; P < .001). The mean lymphocyte count tended to be higher in the preadmission-injury group than in the acute-injury group. In comparison, nucleated RBC values were not correlated as strongly with neonatal hours of life; nucleated RBC counts tended to be higher and persist longer among neonates with preadmission injury than among those with acute injury.Conclusion: Compared with normal levels, both lymphocyte and nucleated RBC counts were elevated among neonates with fetal asphyxial injury. Both counts appear to be more elevated and to remain elevated longer in newborns with preadmission injury than in infants with acute injury. However, the rapid normalization of lymphocyte counts in these injured neonates limits the clinical usefulness of these counts after the first several hours of life.     

Nucleated red blood cell count at birth as an index of perinatal brain damage

OBJECTIVE: The prognostic value of the nucleated red blood cell count at birth with respect to perinatal brain damage and neonatal outcome was assessed in infants at high risk of having neurologic damage. STUDY DESIGN: The nucleated red blood cell count at birth, pulsed Doppler ultrasonography in the cerebral arteries, cranial fontanelle sonograms, and neurodevelopmental status were evaluated in 337 newborn infants. RESULTS: The nucleated red blood cell count at birth was significantly higher (1) in neonates with abnormal Doppler ultrasonographic parameters for the cerebral arteries at 48 to 72 hours after birth than in healthy neonates, (2) in 6-month-old infants with sequelae of hypoxic-ischemic encephalopathy than in healthy infants, and (3) in 3-year-old children with abnormal developmental status than in those with no abnormalities at follow-up. Significant correlations were observed between the nucleated red blood cell count and gestational age, Apgar score at 1 and 5 minutes, pH, base deficit, fraction of inspired oxygen, blood oxygen content, and birth weight. CONCLUSIONS: The nucleated red blood cell count at birth not only reflects a response of the infant to perinatal hypoxia but is also a reliable index of perinatal brain damage.     

Nucleated red blood cells in growth-restricted fetuses: associations with short-term neonatal outcome

OBJECTIVE: To determine the utility of the neonatal nucleated red blood cell (NRBC) count as an independent predictor of short-term perinatal outcome in growth-restricted fetuses. METHODS: Hospital charts of neonates with a discharge diagnosis indicating a birth weight <10th percentile were reviewed for perinatal outcome. We studied all eligible neonates who had a complete blood count on the first day of life. After multiple gestations, anomalous fetuses and diabetic pregnancies were excluded; 73 neonates comprised the study group. Statistical analysis included ANOVA, simple and stepwise regression. RESULTS: Elevated NRBC counts were significantly associated with cesarean section for non-reassuring fetal status, neonatal intensive care unit admission and duration of neonatal intensive care unit stay, respiratory distress and intubation, thrombocytopenia, hyperbilirubinemia, intraventricular hemorrhage and neonatal death. Stepwise regression analysis including gestational age at birth, birth weight and NRBC count demonstrated that in growth-restricted fetuses, NRBC count was the strongest predictor of neonatal intraventricular hemorrhage, neonatal respiratory distress and neonatal death. CONCLUSION: An elevated NRBC count independently predicts adverse perinatal outcome in growth-restricted fetuses.     

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 (r (2) = 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.     

The association of hypotonia and depression in the term and near-term neonate with metabolic acidemia

AIMS: To determine the association of hypotonia and depression in neonates at or near term with metabolic acidemia at birth (umbilical arterial pH<7.0 and base excess <-12 mM). METHODS: This case-control study identified 87 infants without chromosomal or congenital abnormalities born at a single university hospital between 7/91 and 10/04 with hypotonia at birth requiring resuscitation and admission to the neonatal intensive care unit that had a cord gas at delivery. Controls were the subsequent delivery with a cord gas matched by gestational age. RESULTS: Cases and controls did not differ in gestational age (38.7+/-1.9, 38.6+/-1.9 weeks) or birth weight (3,066+/-664, 3,171+/-655 g, P=0.20). Cases were more likely to have a cord pH<7.0 [17 (20%) vs. 1 (1.1%), P=0.0001] and cord pH 7.0-7.1 [13 (14.9%) vs. 2 (2.3%), P=0.003]. Among the hypotonic infants, 31 (35.6%) also were depressed at birth with a 5-min Apgar <7. In the depressed subset of hypotonic neonates 14/31 (45%) had a pH<7.0. Of the 12 hypotonic neonates with seizures, 3 (25%) had pH<7.0. Multivariate analysis showed a significant association between neonatal hypotonia and hypoglycemia, umbilical arterial pH, and nucleated red blood cell count. CONCLUSIONS: Although metabolic acidemia is significantly associated with hypotonia at the time of birth, the majority of neonates with hypotonia and depression or seizures do not have objective evidence of asphyxia as measured by a cord gas at the time of delivery.     

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.     

Neonatal nucleated red blood cell counts in small-for-gestational-age fetuses: relationship to fetoplacental Doppler studies

OBJECTIVE: To study the influence of pathologic umbilical and middle cerebral artery and uterine artery Doppler studies on the nucleated red blood cell count in small-for-gestational-age (SGA) fetuses. MATERIALS AND METHODS: Cord blood was prospectively collected during a 18-month period. 80 SGA fetuses (fetal abdominal circumference < 5th percentile) with Doppler ultrasound of the umbilical, the middle cerebral artery and both uterine arteries were enrolled in the study. SGA fetuses with normal Doppler flow velocity waveforms were allocated to group 1 (n = 23). Group 2 (n = 13) were fetuses with abnormal umbilical Doppler studies and group 3 (n = 44) were fetuses with both, pathologic umbilical and uterine artery Doppler studies. 2 fetuses in group 3 showed evidence of brain sparing, 3 fetuses presented absent-end-diastolic flow in the umbilical artery. Outcome measures included nucleated red blood cell count, Apgar scores, arterial pH and arterial base excess, venous pH, birth weight, gestational age at delivery, mode of delivery, rate of neonatal intensive care unit admission and length of stay in the neonatal intensive care unit. RESULTS: Highest nucleated red blood cell counts with lowest birth weight and gestational age were found in group 3. Decelerations of the fetal heart rate were more frequent in study group 3 and caesarean section for fetal indication was performed more often in this group. Those fetuses had to be transfered more often to the neonatal intensive care unit than fetuses of the other study groups. There was a tendency in group 3 towards lower arterial pH values and arterial base excess values. Fetuses with absent-end-diastolic flow in the umbilical artery presented highest nucleated red blood cell counts. CONCLUSION: In SGA fetuses increasing Doppler pathology seems to be correlated with increasing nucleated red blood cell count post-partum. Pathologic uterine artery flow results might have an additional impact on the number of nucleated red blood cells at birth.     

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.     

Nucleated red blood cells in infants of smoking mothers

OBJECTIVE: To evaluate whether the absolute nucleated red blood cell (RBC) count is elevated in term, appropriate for gestational age (AGA) infants born to smoking women. METHODS: We compared absolute nucleated RBC counts taken during the first 12 hours of life in two groups of term, vaginally delivered, AGA infants, one group born to mothers who smoked during pregnancy (n = 30) and the other born to mothers who did not smoke (n = 30). We excluded infants of women with diabetes, hypertension, or alcohol or drug abuse, and infants with heart rate abnormalities, hemolysis, blood loss, or chromosomal anomalies. RESULTS: There were no differences between the groups in birth weight, gestational age, maternal age, gravidity, parity, maternal analgesia during labor, 1- and 5-minute Apgar scores, corrected white blood cell counts, lymphocyte counts, or hematocrits. The median absolute nucleated RBC count in infants of smoking mothers was 0.5 x 10(9)/L (range 0 to 5.0) versus 0.0005 x 10(9)/L (range 0 to 0.6) in nonsmoking controls (P < .002). Regression analysis that included Apgar scores, gestational age, and number of cigarettes smoked per day showed a significant correlation of absolute nucleated RBC count only with the number of cigarettes smoked per day (P < .001). CONCLUSION: At birth, term AGA infants born to smoking mothers have increased circulating absolute nucleated RBC counts compared with controls. The absolute nucleated RBC count in newborns correlates with the number of cigarettes smoked during pregnancy.     

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.     

Neonatal nucleated red blood cell counts in growth-restricted fetuses: relationship to arterial and venous Doppler studies.

OBJECTIVE: Elevated nucleated red blood cell count in neonatal blood and Doppler-detected circulatory decompensation in fetuses with intrauterine growth restriction are associated with hypoxemia. We sought to determine the relationship between the nucleated red blood cell count at birth and the circulatory status of fetuses with intrauterine growth restriction. STUDY DESIGN: Eighty-four fetuses with elevated umbilical artery pulsatility index values >2 SD above the gestational age mean and a subsequent birth weight <10th percentile were examined serially. Umbilical and middle cerebral artery pulsatility index, inferior vena cava and ductus venosus peak velocity index, and flow pattern in the umbilical vein (umbilical vein constant vs pulsatile) were recorded. Fetuses were grouped as follows, on the basis of the last examination before delivery: 1, elevated umbilical artery pulsatility index only; 2, middle cerebral artery pulsatility index >2 SD below the gestational age mean in addition to abnormal umbilical artery pulsatility index; 3, either peak velocity index >2 SD above the gestational age mean in the inferior vena cava and ductus venosus or pulsatile flow in the umbilical vein, or both. Nucleated red blood cells per 100 white blood cells were ascertained in a peripheral blood sample obtained within 1 hour of delivery with daily follow-up samples until the nucleated red blood cell count was <5/100 white blood cells. RESULTS: Groups 2 (median 38.5, range 1-273) and 3 (median 145, range 2-3180) had higher nucleated red blood cell counts than group 1 (median 8.5, range 1-270) (P <.05 and P <.005, respectively). The persistence of the nucleated red blood cell count elevation was also longer in groups 3 (median 4 days, range 1-19 days) and 2 (median 2. 5 days, range 1-7 days) than in group 1 (median 1 day, range 1-8 days). Neonates in group 3 also had lower platelet count, hemoglobin value, hematocrit value, and white blood cell count. The umbilical cord artery bicarbonate level was the strongest independent determinant of the peak nucleated red blood cell count and persistence of nucleated red blood cell elevation (r (2) = 0.27, P <. 001 and r (2) = 0.47, P <.0001). CONCLUSION: Increasing abnormality of arterial and venous flows in fetuses with intrauterine growth restriction is associated with increasing nucleated red blood cell count at birth. Metabolic acidemia rather than altered PO (2 ) associated with this circulatory state appears to be the main determinant of the rise in nucleated red blood cells.     

Neutrophil function in neonates born to gestational diabetic mothers.

OBJECTIVE: To examine neutrophil functional activity in the cord blood of term neonates born to gestational diabetic mothers, in association with the type of diabetes and the development of neonatal hypoglycemia. METHODS: Neutrophil chemotaxis, random motility, and chemiluminescence was evaluated in the cord blood of 30 healthy term neonates: 12 were born to gestational diabetic mothers who received no-insulin (GDM-NI), eight to gestational diabetic mothers who received insulin (GDM), and 10 to mothers without diabetes (neonatal controls). In addition, the neutrophil functional activity in the peripheral venous blood of 10 healthy adults was analyzed. RESULTS: Neutrophil functional activity in the cord blood of the neonates with and without maternal gestational diabetes was significantly lower than that in adults. As compared to neonatal controls, neonates born to both groups of GDM had decreased chemotaxis, random motility, and chemiluminescence (GDM-NI: 52.8+/-2.1 microm, p<0.001, 42.1+/-4.4 microm, p<0.001, and 140.1+/-6.9 counts per minute (cpm) x 10(3), p<0.01, respectively, and GDM: 53.0+/-1.9 microm, p<0.01, 41.8+/-4.0 microm, p<0.001, and 143.0+/-6.8 cpm x 10(3), p<0.01, respectively). Unlike controls, a tight correlation was identified between the tested neutrophil parameters in the cord blood of neonates born to diabetic mothers (r=0.70 to 0.91). The prevalence of hypoglycemia after birth was almost equal (50.0 to 41.7%) in the two groups of neonates born to diabetic mothers. There were differences in the neutrophil functional activity in the cord blood of the neonates with and without hypoglycemia. CONCLUSION: Maternal gestational diabetes leads to impairment of cord blood neutrophil motility and postphagocytic bactericidal capacity independently from the insulin requirements for the maintenance of normoglycemia during pregnancy.     

Nucleated red blood cells in meconium aspiration syndrome

OBJECTIVE: To evaluate whether the absolute nucleated red blood cell (RBC) count is higher in infants who had meconium aspiration with respiratory symptoms compared with infants with asymptomatic meconium aspiration and controls. METHODS: We compared the absolute nucleated RBC counts during the first 12 hours of life in three groups of term, vaginally delivered infants, including those who had meconium aspiration with respiratory symptoms (n = 11), asymptomatic meconium aspiration (n = 45), and control healthy infants (n = 32). We excluded infants of women with diabetes in pregnancy; hypertension; alcohol, tobacco, or drug abuse; and those with hemolysis, blood loss, or chromosomal anomalies. RESULTS: There were no significant differences among groups in gestational age; gravidity; parity; maternal analgesia; lymphocyte, platelet, and granulocyte counts; and hematocrit. The median nucleated RBC count was significantly higher in the meconium aspiration group with respiratory symptoms (0.007 x 10(9)/L) than the asymptomatic meconium aspiration group (0.004 x 10(9)/L) or controls (0.003 x 10(9)/L). CONCLUSION: At birth, infants with meconium aspiration syndrome had higher absolute nucleated RBC counts compared with infants with asymptomatic meconium aspiration and normal infants.     

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 x 10(9) +/- 5.46 x 10(9)/L compared with 1.37 x 10(9) +/- 1.78 x 10(9)/L calculated from placental sections. These data were normalized by logarithmic transformation. A significant linear regression was obtained, r(2) = 0.74, P <.001. The prediction equation obtained was natural logarithm (newborn nucleated RBC count) is equal to 1.002 x 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.