The relationship between nucleated red blood cell counts and early-onset neonatal seizures

Nucleated Red Blood Cells as a Marker of Acute and Chronic Fetal Hypoxia in a Rat Model

OBJECTIVE

To examine the relationship between duration of fetal hypoxia, nucleated red blood cell (NRBC) count, and fetal growth.

METHODS

Pregnant rats were exposed to a severe hypoxia (9.5%-10% O₂) for varying time intervals (2, 6, 12, 24, 48, and 120 hours; n=4 for each time interval) immediately prior to delivery at term. Normoxic controls were exposed to room air (21% O₂) and matched for all other study variables (n=4 rats for each time interval). Pups were delivered via hysterotomy while maintaining exposure gas concentrations. Blood gas analysis and NRBC counts were performed, and fetal body and liver weights were recorded. Student's t test and simple regression were used for statistical analysis.

RESULTS

As the duration of hypoxia increased, fetal weight, liver weight, blood bicarbonate, and base excess levels decreased significantly; concomitantly, NRBC counts increased. This increase in NRBCs became statistically significant after 24 hours of exposure. After 48 hours of hypoxia there was a 2.5-fold rise in NRBC count, and after 120 hours of hypoxia there was a 4.5-fold rise in NRBC count over control levels. After 12 or more hours of hypoxia, fetal body weights were significantly reduced; 120 hours of hypoxia resulted in a 35% reduction in fetal body weight, a 34% reduction in fetal liver weight, and 356% increase in NRBC count.

CONCLUSION

In a pregnant rat model, chronic maternal hypoxia (≥24 hours) results in a significant increase in fetal NRBC counts as well as reduced fetal body weight and organ growth.

Nucleated red blood cell counts: an early predictor of brain injury and 2-year outcome in neonates with hypoxic-ischemic encephalopathy in the era of cooling-based treatment

BACKGROUND

Raised nucleated red blood cell (NRBC) counts in neonates may indicate in utero hypoxia and brain damage.

OBJECTIVE

The study aimed to examine the use of NRBC counts as a predictor of brain injury and neurodevelopmental outcomes in neonates with hypoxic-ischemic encephalopathy (HIE) treated under current cooling-based strategy.

METHODS

Forty-three neonates with asphyxia between 2004 and 2010 were retrospectively investigated. Twenty neonates with moderate/severe HIE underwent hypothermia (HT), and 23 with mild HIE were treated in normothermia (NT). Neonates were divided into groups according to the presence of cerebral parenchymal lesions on magnetic resonance imaging (MRI) at 2 weeks after birth. All patients were followed-up neurologically for ⩾ 24 months. NRBC counts during the first 3 days were compared between groups.

RESULTS

Eleven HT (HT-N) and 21 NT (NT-N) neonates had normal MRI, and 9 HT (HT-L) and 2 NT (NT-L) neonates had parenchymal lesions. NRBC counts, both absolute and /100 white blood cells (WBC) counts, during the first 3 days in HT-L and NT-L were significantly higher than those in HT-N and NT-N, particularly within 6 hours after birth (HT-N: 502 [0-3060]/mm(3) vs HT-L: 2765 [496-6192]; 0 [0-3417] vs NT-L: 4384 [3978-4789], median [range]). Neonates with /100 white blood cells ⩾ 6/mm(3) and absolute NRBC counts ⩾ 1324/mm(3) within 6 hours of birth had high risks of abnormal MRIs and 2-year outcomes.

CONCLUSIONS

NRBC counts can predict brain injury and neurological outcomes in cooled and non-cooled asphyxiated neonates.

Hematologic profile of the fetus with systemic inflammatory response syndrome

OBJECTIVE

The fetal inflammatory response syndrome (FIRS) is associated with impending onset of preterm labor/delivery, microbial invasion of the amniotic cavity and increased perinatal morbidity. FIRS has been defined by an elevated fetal plasma interleukin (IL)-6, a cytokine with potent effects on the differentiation and proliferation of hematopoietic precursors. The objective of this study was to characterize the hematologic profile of fetuses with FIRS.

STUDY DESIGN

Fetal blood sampling was performed in patients with preterm prelabor rupture of membranes and preterm labor with intact membranes (n=152). A fetal plasma IL-6 concentration ≥ 11 pg/mL was used to define FIRS. Hemoglobin concentration, platelet count, total white blood cell (WBC) count, differential count, and nucleated red blood cell (NRBC) count were obtained. Since blood cell count varies with gestational age, the observed values were corrected for fetal age by calculating a ratio between the observed and expected mean value for gestational age.

RESULTS

1) The prevalence of FIRS was 28.9% (44/152); 2) fetuses with FIRS had a higher median corrected WBC and corrected neutrophil count than those without FIRS (WBC: median 1.4, range 0.3-5.6, vs. median 1.1, range 0.4-2.9, P=0.001; neutrophils: median 3.6, range 0.1-57.5, vs. median 1.8, range 0.2-13.9, P<0.001); 3) neutrophilia (defined as a neutrophil count >95th centile of gestational age) was significantly more common in fetuses with FIRS than in those without FIRS (71%, 30/42, vs. 35%, 37/105; P<0.001); 4) more than two-thirds of fetuses with FIRS had neutrophilia, whereas neutropenia was present in only 4.8% (2/42); 5) FIRS was not associated with detectable changes in hemoglobin concentration, platelet, lymphocyte, monocyte, basophil or eosinophil counts; and 6) fetuses with FIRS had a median corrected NRBC count higher than those without FIRS. However, the difference did not reach statistical significance (NRBC median 0.07, range 0-1.3, vs. median 0.04, range 0-2.3, P=0.06).

CONCLUSION

The hematologic profile of the human fetus with FIRS is characterized by significant changes in the total WBC and neutrophil counts. The NRBC count in fetuses with FIRS tends to be higher than fetuses without FIRS.

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 >or=26 per 100 white blood cells (%) or the development of a platelet count <or=100,000 per mm(3) 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 >or=26% was: group 1, 10/21 (47.6%); group 2, 0/14 (0%); group 3, 0/12 (0%). Those with a platelet count <or=100,000 per mm(3): 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 >or=26% than group 3 (p = 0.0135). A platelet count <or=100,000 per mm(3) 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 >or=26% and/or a platelet count <or=100,000 per mm(3) within five days of birth is inconsistent with acute birth asphyxia.

Elevated circulating fetal nucleated red blood cells and placental pathology in term infants who develop cerebral palsy

An elevated circulating fetal nucleated red blood cell count has long been recognized as an indicator of significant intrauterine stress. However, the nature of the causative events and their timing remain controversial. In this study, subacute and chronic placental lesions known to be associated with neurodisability were used as surrogates for antenatal stress. Mother-infant pairs with complete blood counts within 2 hours of delivery (n = 81) were drawn from a larger database of 152 term infants with cerebral palsy. An elevated nucleated red blood cell count (2.5 x 10(3)/mm(3)) in these infants was associated with a significantly increased prevalence of subacute or chronic placental lesions, whereas clinical findings did not significantly differ. The number of nucleated red blood cells per 10 high-power fields of villous parenchyma was directly correlated with the nucleated red blood cell count, and a threshold of 10 or more nucleated red blood cells predicted a nucleated red blood cell count greater than 2.5 x 10(3)/mm(3). Among individual placental lesions, multiple foci of avascular villi and chronic villitis were significantly associated with an elevated nucleated red blood cell count, whereas meconium-associated vascular necrosis showed a borderline association. Acute chorioamnionitis was the only placental lesion more common in the group without elevated nucleated red blood cell count. The presence of significant placental lesions was associated with an elevated nucleated red blood cell count in infants with or without either acidosis (cord pH <7.0) or birth asphyxia (American College of Obstetrics and Gynecology criteria). Acidosis and birth asphyxia were not significantly related to an elevated nucleated red blood cell count in infants without these placental lesions.

Nucleated red blood cells are a direct response to mediators of inflammation in newborns with early-onset neonatal sepsis

OBJECTIVE

The objective of the study was to test the hypothesis that inflammation modulates fetal erythroblastosis and/or the release of nucleated red blood cells (NRBCs) independent of hypoxia or fetal stress. We sought to determine whether fetal inflammation is associated with an elevation in neonatal NRBC count in the setting of inflammation-associated preterm birth.

STUDY DESIGN

The relationships between peripheral NRBC count, histological chorioamnionitis, umbilical cord interleukin (IL)-6, erythropoietin (EPO), cortisol, and acid-base status were analyzed in 68 preterm singletons, born to mothers who had an amniocentesis to rule out infection. Proteomic profiling of amniotic fluid identified presence of intraamniotic inflammation according to established parameters. NRBC counts were assessed within 1 hour of birth. Early-onset neonatal sepsis (EONS) was established based on hematological and microbiological indices. IL-6, EPO, and cortisol levels were measured by immunoassays. Fetal acid-base status was determined within 10 minutes of delivery. Parametric or nonparametric statistics were used.

RESULTS

Fetuses with EONS (n = 19) were delivered at earlier gestational ages (mean +/- SD: 27.1 +/- 2.8 weeks, P = .001) and more often by mothers with intraamniotic inflammation (P = .022) and histological chorioamnionitis (P < .001). Neonates with EONS had higher absolute NRBC counts (P = .011). NRBC counts were directly correlated with cord blood IL-6 levels (P < .001) but not with EPO, cortisol or parameters of acid-base status levels regardless of EONS status. These relationships remained following correction for gestational age, diabetes, intrauterine growth restriction, and steroid exposure.

CONCLUSION

In the setting of inflammation-associated preterm birth and in the absence of hypoxia, elevations in NRBCs in the early neonatal period may be a direct response of exposure to inflammatory mediators in utero.

Nucleated red blood cell counts in the first week of life: a critical appraisal of relationships with perinatal outcome in preterm growth-restricted neonates

OBJECTIVE

Nucleated red blood cells (NRBC) are fetal hematologic markers for placental dysfunction, hypoxemia, and asphyxia. NRBC count elevation at birth or persistence is linked statistically to adverse outcome, but clinical predictive value is variable. We studied novel indices to better define overall magnitude of NRBC response.

STUDY DESIGN

Peripheral NRBC count was obtained from preterm (<34 weeks of gestation) growth-restricted neonates within 2 hours of life. Daily counts and duration of NRBC count >30/100 white blood cells were determined. Mean counts (NRBC-mean), area under the curve (NRBC-AUC), and declination (NRBC-slope) were analyzed over week 1. NRBC parameters were related to major morbidity (bronchopulmonary dysplasia, grade III/IV intraventricular hemorrhage, necrotizing enterocolitis included) and neonatal death (NND).

RESULTS

Twenty-two of 176 patients (12.5%) had acidosis. Complications included bronchopulmonary dysplasia (n = 36; 20.5%), intraventricular hemorrhage (n = 18; 10.2%), necrotizing enterocolitis (n = 18; 10.2%), NND (n = 18; 10.2%). NRBC-AUC and NRBC-mean correlated most strongly with pH, birthweight, and gestational age (Pearson coefficient -0.45 to -0.18; all P < .001). NRBC-AUC varied most between nonmorbid and morbid; NRBC-mean varied most between survivors and NND (all P < .001). NRBC persistence strongly predicted NND: clearance by day 4 was achieved by 80% of survivors and only 35% of NNDs. Logistic regression identified prematurity and persistent NRBC counts as primary morbidity determinants (r2 = 0.56; P < .01). Although the importance of individual NRBC counts varied, day-4 NRBC counts of >70 predicted morbidity best (sensitivity, 82%; specificity, 96%). Presence of morbidity and birthweight were prime determinants of death (r2 = 0.42; P < .01).

CONCLUSION

Simple daily NRBC counts provide clinical information that is equivalent to more complicated methods. The importance of prematurity and growth are emphasized, but elevated NRBC counts beyond day 3 are relevant independent predictors of adverse outcome.

Are placental chorionic capillary nucleated red blood cell counts useful compared to umbilical cord blood tests?

OBJECTIVE

To compare measurement of fetal nucleated red blood cell (NRBC) counts in paired histologic samples of the placenta and umbilical cord bloods.

METHOD

Forty-five randomly selected pregnancies had two determinations of the NRBC count. A sample of umbilical venous blood had a NRBC count measured and sections of the placenta were examined for their villous capillary NRBC counts.

RESULTS

Umbilical venous blood had NRBC/100 white blood cell counts ranging from 0 to 67. Paired evaluation of placental tissue had NRBC counts of 0-5 with 60% being zero compared to 8% zero counts in cord blood. There was no correlation between the paired counts (R(2) = 0.04).

CONCLUSION

Umbilical cord blood provides different information on fetal NRBC count than does histologic study of the placenta.

The Timing of Neonatal Brain Damage

Although neonatal morbidity and mortality are less than in the past, the risk of pre-natal and neonatal brain damage has not been eliminated. In order to optimize pre-natal, perinatal and neonatal care, it is necessary to detect factors responsible for brain damage and obtain information about their timing. Knowledge of the timing of asphyxia, infections and circulatory abnormalities would enable obstetricians and neonatologists to improve prevention in pre-term and full-term neonates. Cardiotocography has been criticized as being too indirect a sign of fetal condition and as having various technical pitfalls, though its reliability seems to be improved by association with pulse oximetry, fetal blood pH and electrocardiography. Neuroimaging is particularly useful to determine the timing of hypoxic-ischemic brain damage. Cranial ultrasound has been used to determine the type and evolution of brain damage. Magnetic resonance has also been used to detect antenatal, perinatal and neonatal abnormalities and timing on the basis of standardized assessment of brain maturation. Advances in the interpretation of neonatal electroencephalograms have also made this technique useful for determining the timing of brain lesions. Nucleated red blood cell count in cord blood has been recognized as an important indication of the timing of pre-natal hypoxia, and even abnormal lymphocyte and thrombocyte counts may be used to establish pre-natal asphyxia. Cord blood pH and base excess are well-known markers of fetal hypoxia, but are best combined with heart rate and blood pressure. Other markers of fetal and neonatal hypoxia useful for determining the timing of brain damage are assays of lactate and markers of oxidative stress in cord blood and neonatal blood. Cytokines in blood and amniotic fluid may indicate chorioamnionitis or post-natal infections. The determination of activin and protein S100 has also been proposed. Obstetricians and neonatologists can therefore now rely on various methods for monitoring the risk of brain damage in the antenatal and post-natal periods.

Prediction of seizures in asphyxiated neonates: correlation with continuous video-electroencephalographic monitoring

BACKGROUND

After perinatal asphyxia, predicting which infants will develop significant hypoxic-ischemic encephalopathy and neonatal seizures remains a difficult task. High-risk markers (Apgar score, acidosis, nucleated red blood cells, and resuscitation) have been used to predict neonatal seizures with varying success. The "3 strikes" of Apgar score of <5 at 5 minutes, pH <7.00, and need for intubation have been cited as having a positive predictive value of 80%. We examined whether the predictive values of these markers would be increased if early continuous electroencephalographic monitoring allowed us to accurately identify all neonatal seizures and to grade the encephalopathy.

METHOD

We recruited term infants with perinatal asphyxia. Continuous video electroencephalography was commenced soon after birth and continued for 24 to 72 hours. The abilities of high-risk markers to predict electroencephalographic seizures, background electroencephalographic activity, and Sarnat grade were examined.

RESULTS

Forty-nine infants were suitable for analysis. Electrographic seizures occurred in 11 of the 49 infants. Encephalopathy was scored by using Sarnat grade (6, severe; 18, moderate; 25, mild) and electroencephalographic findings (4 inactive, 4 major abnormalities, 16 moderate abnormalities, and 25 normal/mildly abnormal). Apgar score of <5 at 5 minutes, pH <7.0, and the need for intubation had positive predictive values for neonatal seizures of 18%, 16%, and 21%, respectively. Combining these markers gave a positive predictive value of 25% and a negative predictive value of 77%. Substituting base deficit or lactate for pH in the 3-strikes model did not improve its predictive value. Apgar score of <5 at 5 minutes, nucleated red blood cells, and a base deficit less than -15 mEq/L showed some association with Sarnat grade. Only 5-minute Apgar score was significantly associated with both Sarnat grade and electroencephalographic grade.

CONCLUSION

After perinatal asphyxia, neither the condition at birth nor the degree of metabolic acidosis reliably predict neonatal seizures.

Apgar Scores and Long-Term Risk of Epilepsy

BACKGROUND

Low Apgar scores are associated with high risk of neonatal death, cerebral palsy, and mental retardation, but the association between Apgar scores and long-term risk of epilepsy remains unresolved.

METHODS

We carried out a population-based cohort study of 1,538,732 live newborns in Denmark between 1 January 1978 and 31 December 2002 by using national registers. The Apgar scores at 1 or 5 minutes were recorded by midwives following standardized procedures. We obtained information on epilepsy by linking the cohort with the National Hospital Register. Cohort members were followed from birth until onset of epilepsy, death, emigration, or 31 December 2002, whichever came first.

RESULTS

The incidence rate of epilepsy increased consistently with decreasing Apgar scores. The incidence rate of epilepsy was 628 per 100,000 person-years for those with 5-minute Apgar scores of 1 to 3 and 86 per 100,000 person-years for those with a score of 10; the resulting incidence rate ratio was 7.1 (95% confidence interval = 5.8-8.8). The incidence rate ratios of epilepsy associated with low Apgar scores were particularly high in early childhood but remained high into adulthood. The association did not change after excluding children with cerebral palsy, congenital malformations, or a parental history of epilepsy.

CONCLUSIONS

Neonates with a suboptimal Apgar score have a higher risk of epilepsy that lasts into adult life. These findings suggest that prenatal or perinatal factors play a larger role in the etiology of epilepsy than has previously been recognized.

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 Uncomplicated Prolonged Pregnancy

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

The findings of this study suggest that elevated NRBC counts are associated with specific pregnancy complications rather than uncomplicated prolonged pregnancies in general.

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.

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.

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.

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 < or =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, R (2) = 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.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Fetal and neonatal neurologic consultations: identifying brain disorders in the context of fetal-maternal-placental disease

Pediatric neurologists provide an important consultative role for the fetus or neonate with a suspected brain disorder. Although most consultations are initiated after birth, neonatal neurologic dysfunction may be reflective of fetal brain damage or maldevelopment. Maternal or placental/cord disease states can predispose the fetus or neonate to brain disorders during the antepartum, intrapartum, or early postpartum periods. Neurologists must therefore consider maternal, placental, and fetal conditions on which a neonatal encephalopathy may be superimposed, with or without recent brain injury. This review suggests how the pediatric neurologist can contribute more effectively to fetal and neonatal neurologic evaluations regarding etiologies and mechanisms of brain injury; their role will enhance diagnostic services composed of maternal-fetal specialists, placental and pediatric pathologists, neonatologists, neurosurgeons, geneticists, and other pediatric subspecialists. Selected examples of structural markers during fetal life, and functional markers during neonatal life, illustrate the wide spectrum of disease states that are highly dependent on the timing and location of brain injury. The pediatric neurologist has the opportunity to integrate these complementary lines of investigation into a responsive consultative opinion, which is both medically accurate and ethical, responsible to the welfare of the mother and child.

Perinatal asphyxia: timing and mechanisms of injury in neonatal encephalopathy

This article summarizes the recent medical literature regarding perinatal asphyxia with respect to timing and mechanisms of injury for neonates who were clinically diagnosed with an encephalopathy in the newborn period. Multiple mechanisms of injury are reviewed, including genetic vulnerability, acquired inflammatory responses, and clotting defects that can lead to ischemic-induced brain damage. Before effective treatments for fetal and neonatal brain disorders can be developed, accurate and timely diagnoses of fetal or neonatal brain injury must be achieved. Specific subsets of children can then benefit from neuroprotective strategies that can target the specific developmental aspects of brain adaptation or plasticity relative to the specific etiology and timing of injury after asphyxia.