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Prediction of perinatal asphyxia with nucleated red blood cells in cord blood of newborns
International Journal of Gynecology and Obstetrics 81 (2003) 267–271
Article
Prediction of perinatal asphyxia with nucleated red blood cells in cord blood of newborns B. Ghosh, S. Mittal*, S. Kumar, V. Dadhwal Department of Obstetrics And Gynecology, All India Institute of Medical Sciences, New Delhi, India Received 20 November 2002; received in revised form 3 March 2003; accepted 6 March 2003
Abstract 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 (rsy0.50, P-0.001 and rsy0.48, P-0.001, respectively). Positive correlation was demonstrated with evidence of chronic antepartum asphyxia, presence of pregnancy induced hypertension and intrauterine growth restriction (rs2.66, Ps0.02). 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. 䊚 2003 International Federation of Gynecology and Obstetrics. Published by Elsevier Science Ireland Ltd. All rights reserved. Keywords: Perinatal asphyxia; Nucleated red blood cells; Cord blood
1. Introduction Perinatal asphyxia remains a significant cause of perinatal morbidity and mortality the world over, and is known to complicate up to 5–10% of all deliveries w1x. Currently used parameters to *Corresponding author. Tel.: q91-11-2659-3378; fax: q9111-265-88449. E-mail address: [email protected] (S. Mittal).
predict or define perinatal asphyxia are: Apgar score, umbilical arterial acidemiaybase excess, intrapartum electronic fetal monitoring, fetal scalp pH measurement and presence of meconium in amniotic fluid. However, to date no single marker of perinatal asphyxia has shown good predictive efficacy and only a combination of various indices can help in early diagnosis of perinatal asphyxia w2 x .
0020-7292/03/$30.00 䊚 2003 International Federation of Gynecology and Obstetrics. Published by Elsevier Science Ireland Ltd. All rights reserved. doi:10.1016/S0020-7292(03)00124-3
268
B. Ghosh et al. / International Journal of Gynecology and Obstetrics 81 (2003) 267–271
Recently, nucleated red blood cell count (NRBC) per 100 white blood cells (WBC) in umbilical venous blood of newborns has been reported as a marker of perinatal asphyxia. It is based on the fact that any hypoxic event induces a fetal compensatory response in the form of exaggerated erythropoesis, resulting in influx of immature red blood cells into fetal circulation, levels of which may be correlated with the presence of perinatal asphyxia. The present study was done to evaluate the significance of the presence of NRBC per 100 WBC in umbilical venous blood in the prediction of perinatal asphyxia and to compare this with established markers such as Apgar score and umbilical arterial pH value. 2. Methods A prospective case controlled study was conducted at the All India Institute of Medical Sciences between August 1999 and March 2001. A total of 75 newborns were included in the study. All babies in both the groups were term (G37 completed weeks), with a period of gestation ranging from 37q0 –40q6 weeks. Group I (ns26) included newborns with evidence of perinatal asphyxia. All newborns in this group had a 1 min Apgar score of -6y10 along with an umbilical arterial pH of F7.15. Group II (ns49), the control group, included newborns having a 1 min Apgar score of )6y10 and an umbilical arterial pH of )7.15. This was based on earlier evidence that fetal acidemia defined by an umbilical arterial blood pH of less than 7.2 denotes an arbitrarily high level and a lower normal range up to 7.15 has been reported in normal uncomplicated pregnancies w3x. Pregnancies known to be associated with an elevated NRBC count in fetalyneonatal blood (i.e. Rh isoimmunization, maternal anemia, diabetes mellitus, multiple pregnancy and preterm deliveries) were excluded from the study w4–7x. Immediately after delivery of the placenta, umbilical arterial blood was collected from a doubly clamped segment of cord into a pre-heparinized capillary tube. At the same time, 1.5 ml of umbilical venous blood was collected using a syringe
into a vial containing EDTA. Both samples were processed immediately and in case of any unforeseen delay, the samples were refrigerated. A thin blood smear was made of the venous blood and studied under 40= magnification. The umbilical arterial pH, pCO2 and pO2 values were determined. Along with the NRBC per 100 WBC count, other hematological parameters noted were hemoglobin level, RBC count, WBC count, hematocrit, mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC). All data were statistically analyzed using SPSS statistics software. Descriptive statistics, i.e. mean"standard deviation were calculated for every continuous variable in the study and frequency distribution tables were made for the categorical variables. To compute the correlation between two quantitative variables, Pearson’s correlation coefficient was applied. To compute the difference between the asphyxiated and the non-asphyxiated group, Student’s t-test, x2-test or Fischer’s exact test was applied as appropriate. Odds ratios w95% confidence interval (C.I.)x were computed to derive the strength of association between various parameters and the outcome. A P-value of -0.05 was considered statistically significant. 3. Results NRBC per 100 WBC levels were estimated at birth in umbilical venous sample and results were compared between the asphyxiated newborns (group I, ns26) and the newborns with no evidence of perinatal asphyxia (group II, ns49). Both the groups were comparable with regard to age and parity of the mothers, period of gestation, mode of delivery, total duration of labor, birth weight and sex of the neonate (Table 1). All neonates in group I had an Apgar score at 1 min of -6y10 and an umbilical arterial pH value of -7.15 with a median Apgar score of 3 and a mean ("S.D.) pH value of 7.06 ("0.12). In group II, all newborns had an Apgar score at 1 min of G6y10 with median Apgar score of 9 and umbilical arterial pH of )7.15 with a mean ("S.D.) value of 7.29 ("0.039). It was seen that the proportion of neonates with meconium staining of liquor as well as admission
B. Ghosh et al. / International Journal of Gynecology and Obstetrics 81 (2003) 267–271
269
Table 1 Patient characteristics of newborns in group I and group II Variable Maternal age: mean ("S.D.) in years Parity: n (%) Primigravida Multigravida Period of gestation: mean ("S.D.) in days Mode of delivery: n (%) Vaginal Cesarean section Total duration of labor: mean ("S.D.) in hours Sex of neonate: n (%) Male Female Birth weight of neonates: mean ("S.D.) in kg
Group I (ns26)
Group II (ns49)
27.19 ("3.82)
26.73 ("4.40)
11 (42.3%) 15 (57.7%) 273.15 ("8.83)
18 (36.7%) 31 (63.3%) 272.40 ("7.76)
17 (65.3%) 9 (34.6%) 11.83 ("4.77)
34 (69.3%) 15 (30.6%) 10.62 ("3.25)
15 (57.7%) 11 (42.3%) 2.8 ("0.5)
23 (46.94%) 26 (53.06%) 2.8 ("0.47)
P-value 0.66 0.82
0.7146 0.9254
0.4054 0.506
rates to NICU was significantly higher in group I compared with group II (P-0.001). Also, 10 (38.4%) newborns in group I developed evidence of hypoxic ischemic encephalopathy and two babies died in the early neonatal period. No such adverse neonatal outcome was observed in group II (Table 2). When followed-up to the age of 16 weeks, none of the babies in either group showed any neurologic impairment when neurologic development was assessed using the Gessel infant development schedule. However, further follow-up is required before any conclusions can be drawn regarding the long-term outcome of the babies. In group I, the mean ("S.D.) NRBC per 100 WBC was 16.5 ("6.4), range 3–25. This was
0.7797
significantly higher than the values in group II, in which mean ("S.D.) was 8.6 ("7.01), with a range of 1–26 (P-0.001). Other hematological parameters were also estimated in umbilical venous blood and the hemoglobin (Hb) level, packed cell volume (PCV) and red blood cell (RBC) count were significantly higher in the group I neonates (Table 3). The NRBC per 100 WBC count correlated well with Apgar score and umbilical arterial pH. The correlation coefficient (r) between NRBC per 100 WBC and Apgar score at 1 min was y0.50 (P0.001) while that between NRBC per 100 WBC count and pH was y0.48 (P-0.001). There was also a statistically significant correlation of NRBC per 100 WBC count in neonates of group I and
Table 2 Comparison of neonatal outcomes of group I and II Parameter
Group I (ns26)
Group II (ns49)
P-value
Meconium staining of liquor
15 (57.7%)
12 (24.5%)
NICU admission
20 (76.9%)
2 (4.1%)
Presence of HIE in newborn
10 (38.4%)
0 (0%)
2 (7.7%)
0 (0%)
Ps0.009, O.R. 4.2 (C.I. 1.4–13.3) P-0.001, O.R. 78.3 (C.I. 12.5–288.9) P-0.001, O.R. not calculable 0.117
Early neonatal death
270
B. Ghosh et al. / International Journal of Gynecology and Obstetrics 81 (2003) 267–271
Table 3 Hematological parameters in umbilical venous blood of neonates in group I and II Hematological parameters
Group I (ns26) mean"S.D.
Group II (ns29) mean"S.D.
P-value
NRBCy100 WBC WBC count=103 ymm3 Hb (gmydl) RBC count (=106 ymm3) PCV (%) MCH (pg) MCHC (g%)
16.5"6.4 13.966"3.05 15.7"0.88 4.9"0.30 51.5"3.7 31.6"1.4 30.6"2.0
8.6"7.01 12.804"2.80 14.6"1.11 4.7"0.46 47.4"4.18 31.4"3.7 30.9"2.6
0.001 0.102 0.000 0.005 0.001 0.721 0.597
MCHC levels (rsy0.49, Ps0.012) as well as development of HIE (rs2.2, Ps0.037). The neonates in group II (non-asphyxiated group) demonstrated significant correlation between NRBC per 100 WBC count and period of gestation (rs y0.29, Ps0.037), birth weight of babies (rs y0.51, P-0.001) and presence of PIH andyor IUGR (ts2.66, Ps0.025). There was no significant correlation of NRBC count with mode of delivery, duration of labor or the presence of meconium in either group. 4. Discussion Nucleated red blood cells are commonly seen in the cord blood of healthy newborns at birth. In term non-asphyxiated newborns, the number of nucleated red blood cells is variable but is only rarely higher than 10 w2,4,8,9x. In our study the results in non-asphyxiated newborns (group II) are in keeping with previous observations w2,4,8,9x. Previous investigators have suggested that nucleated red blood cells increase in response to an asphyxial event w6,9–11x. Also in the present study, a statistically significant correlation was demonstrated between NRBC per 100 WBC count and presence of IUGR andyor PIH (evidence of chronic antepartum hypoxia), Apgar score at 1 min of birth and the umbilical arterial pH value at birth (evidence of acute intrapartum hypoxia). Data from our study did not indicate any significant correlation between NRBC counts and the mode of delivery (vaginal delivery vs. cesarean section), as well as duration of labor. Similar findings have been reported previously w9,11x.
In the past, studies have shown higher nucleated RBC levels in neonates with evidence of neurological impairment w6,10,12,13x. The findings in the present study are consistent with previous studies, and a significantly higher NRBC per 100 WBC count was found in those who developed hypoxic ischemic encephalopathy in the early neonatal period. To conclude, estimating the number of nucleated RBC per 100 WBC in umbilical venous sample of newborns is a simple test, the sample being obtained non-invasively from an otherwise discarded specimen and analyzed by personnel on equipment readily available in most hospital laboratories. The level of nucleated RBC per 100 WBC correlates both with acute intrapartum asphyxia as well as chronic antepartum hypoxia and can be used as a reliable index of early neonatal outcome. The study followed infants to 16 weeks of age and may not be able to state conclusions regarding chronic outcomes. References w1x Low JA. The role of blood gas and acid-base assessment in the diagnosis of intrapartum fetal asphyxia. Am J Obstet Gynecol 1988;159:1235 –1240. w2x Gilstrap LC, Kenneth J, Leveno Burris J, William ML, Little BB. Diagnosis of birth asphyxia on the basis of fetal pH, Apgar score and newborn cerebral dysfunction. Am J Obstet Gynecol 1989;161:825 –830. w3x ACOG Committee Opinion: Committee on Obstetric Practice. Number 138. Utility of umbilical cord blood acid-base assessment. Int J Gynecol Obstet 1994;45:303. w4x Hanlon-Lundberg KM, Kirby RS, Gandhi S, Broekhuizen FF. Nucleated red blood cells in cord blood of singleton term neonates. Am J Obstet Gynecol 1997;176:1149 –1156.
B. Ghosh et al. / International Journal of Gynecology and Obstetrics 81 (2003) 267–271 w5x Green DW, Mimouni F. Nucleated erythrocytes in healthy and in infants of diabetic mothers. J Pediatr 1990;116:129 –131. w6x Philip AGS, Tito AM. Increased nucleated red blood cell counts in small for gestational age infants with very low birth weight. Am J Dis Child 1989;143:164 –169. w7x Snijders RJM, Abbas A, Melby O, Ireland RM, Nicolaides KH. Fetal plasma erythropoietin concentration in severe growth retardation. Am J Obstet Gynecol 1993;168:615 –619. w8x Phelan JP, Ahn MO, Korst LM, Martin GI. Nucleated red blood cells: a marker for fetal asphyxia? Am J Obstet Gynecol 1995;173:1380 –1384. w9x Hanlon-Lundberg KM, Kirby RS. Nucleated red blood cells as a marker of acidemia in term neonates. Am J Obstet Gynecol 1999;181:196 –201.
271
w10x Saracouglu F, Sahin I, Eser E, Gol K, Turkkani B. Nucleated red blood cells as a marker in acute and chronic fetal asphyxia. Int J Gynecol Obstet 2000;71:113 –118. w11x Korst LM, Phelan JP, Ahn MO, Martin GI. Nucleated red blood cells: an update on the marker for fetal asphyxia. Am J Obstet Gynecol 1996;175:843 –846. w12x Thilaganathan B, Athanasiou S, Ozmen S, Creighton S, Watson NR, Nicholaides KH. Umbilical cord blood erythroblast count as an index of intrauterine hypoxia. Arch Dis Child 1994;70:F192 –F194. w13x Blackwell SC, Refuerzo JS, Wolfe HM, Hassan SS, Berry SM, Sokoi RJ, et al. The relationship between nucleated red blood cell counts and early onset neonatal seizures. Am J Obstet Gynecol 2000;182:1452 –1457.
Article
Prediction of perinatal asphyxia with nucleated red blood cells in cord blood of newborns B. Ghosh, S. Mittal*, S. Kumar, V. Dadhwal Department of Obstetrics And Gynecology, All India Institute of Medical Sciences, New Delhi, India Received 20 November 2002; received in revised form 3 March 2003; accepted 6 March 2003
Abstract 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 (rsy0.50, P-0.001 and rsy0.48, P-0.001, respectively). Positive correlation was demonstrated with evidence of chronic antepartum asphyxia, presence of pregnancy induced hypertension and intrauterine growth restriction (rs2.66, Ps0.02). 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. 䊚 2003 International Federation of Gynecology and Obstetrics. Published by Elsevier Science Ireland Ltd. All rights reserved. Keywords: Perinatal asphyxia; Nucleated red blood cells; Cord blood
1. Introduction Perinatal asphyxia remains a significant cause of perinatal morbidity and mortality the world over, and is known to complicate up to 5–10% of all deliveries w1x. Currently used parameters to *Corresponding author. Tel.: q91-11-2659-3378; fax: q9111-265-88449. E-mail address: [email protected] (S. Mittal).
predict or define perinatal asphyxia are: Apgar score, umbilical arterial acidemiaybase excess, intrapartum electronic fetal monitoring, fetal scalp pH measurement and presence of meconium in amniotic fluid. However, to date no single marker of perinatal asphyxia has shown good predictive efficacy and only a combination of various indices can help in early diagnosis of perinatal asphyxia w2 x .
0020-7292/03/$30.00 䊚 2003 International Federation of Gynecology and Obstetrics. Published by Elsevier Science Ireland Ltd. All rights reserved. doi:10.1016/S0020-7292(03)00124-3
268
B. Ghosh et al. / International Journal of Gynecology and Obstetrics 81 (2003) 267–271
Recently, nucleated red blood cell count (NRBC) per 100 white blood cells (WBC) in umbilical venous blood of newborns has been reported as a marker of perinatal asphyxia. It is based on the fact that any hypoxic event induces a fetal compensatory response in the form of exaggerated erythropoesis, resulting in influx of immature red blood cells into fetal circulation, levels of which may be correlated with the presence of perinatal asphyxia. The present study was done to evaluate the significance of the presence of NRBC per 100 WBC in umbilical venous blood in the prediction of perinatal asphyxia and to compare this with established markers such as Apgar score and umbilical arterial pH value. 2. Methods A prospective case controlled study was conducted at the All India Institute of Medical Sciences between August 1999 and March 2001. A total of 75 newborns were included in the study. All babies in both the groups were term (G37 completed weeks), with a period of gestation ranging from 37q0 –40q6 weeks. Group I (ns26) included newborns with evidence of perinatal asphyxia. All newborns in this group had a 1 min Apgar score of -6y10 along with an umbilical arterial pH of F7.15. Group II (ns49), the control group, included newborns having a 1 min Apgar score of )6y10 and an umbilical arterial pH of )7.15. This was based on earlier evidence that fetal acidemia defined by an umbilical arterial blood pH of less than 7.2 denotes an arbitrarily high level and a lower normal range up to 7.15 has been reported in normal uncomplicated pregnancies w3x. Pregnancies known to be associated with an elevated NRBC count in fetalyneonatal blood (i.e. Rh isoimmunization, maternal anemia, diabetes mellitus, multiple pregnancy and preterm deliveries) were excluded from the study w4–7x. Immediately after delivery of the placenta, umbilical arterial blood was collected from a doubly clamped segment of cord into a pre-heparinized capillary tube. At the same time, 1.5 ml of umbilical venous blood was collected using a syringe
into a vial containing EDTA. Both samples were processed immediately and in case of any unforeseen delay, the samples were refrigerated. A thin blood smear was made of the venous blood and studied under 40= magnification. The umbilical arterial pH, pCO2 and pO2 values were determined. Along with the NRBC per 100 WBC count, other hematological parameters noted were hemoglobin level, RBC count, WBC count, hematocrit, mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC). All data were statistically analyzed using SPSS statistics software. Descriptive statistics, i.e. mean"standard deviation were calculated for every continuous variable in the study and frequency distribution tables were made for the categorical variables. To compute the correlation between two quantitative variables, Pearson’s correlation coefficient was applied. To compute the difference between the asphyxiated and the non-asphyxiated group, Student’s t-test, x2-test or Fischer’s exact test was applied as appropriate. Odds ratios w95% confidence interval (C.I.)x were computed to derive the strength of association between various parameters and the outcome. A P-value of -0.05 was considered statistically significant. 3. Results NRBC per 100 WBC levels were estimated at birth in umbilical venous sample and results were compared between the asphyxiated newborns (group I, ns26) and the newborns with no evidence of perinatal asphyxia (group II, ns49). Both the groups were comparable with regard to age and parity of the mothers, period of gestation, mode of delivery, total duration of labor, birth weight and sex of the neonate (Table 1). All neonates in group I had an Apgar score at 1 min of -6y10 and an umbilical arterial pH value of -7.15 with a median Apgar score of 3 and a mean ("S.D.) pH value of 7.06 ("0.12). In group II, all newborns had an Apgar score at 1 min of G6y10 with median Apgar score of 9 and umbilical arterial pH of )7.15 with a mean ("S.D.) value of 7.29 ("0.039). It was seen that the proportion of neonates with meconium staining of liquor as well as admission
B. Ghosh et al. / International Journal of Gynecology and Obstetrics 81 (2003) 267–271
269
Table 1 Patient characteristics of newborns in group I and group II Variable Maternal age: mean ("S.D.) in years Parity: n (%) Primigravida Multigravida Period of gestation: mean ("S.D.) in days Mode of delivery: n (%) Vaginal Cesarean section Total duration of labor: mean ("S.D.) in hours Sex of neonate: n (%) Male Female Birth weight of neonates: mean ("S.D.) in kg
Group I (ns26)
Group II (ns49)
27.19 ("3.82)
26.73 ("4.40)
11 (42.3%) 15 (57.7%) 273.15 ("8.83)
18 (36.7%) 31 (63.3%) 272.40 ("7.76)
17 (65.3%) 9 (34.6%) 11.83 ("4.77)
34 (69.3%) 15 (30.6%) 10.62 ("3.25)
15 (57.7%) 11 (42.3%) 2.8 ("0.5)
23 (46.94%) 26 (53.06%) 2.8 ("0.47)
P-value 0.66 0.82
0.7146 0.9254
0.4054 0.506
rates to NICU was significantly higher in group I compared with group II (P-0.001). Also, 10 (38.4%) newborns in group I developed evidence of hypoxic ischemic encephalopathy and two babies died in the early neonatal period. No such adverse neonatal outcome was observed in group II (Table 2). When followed-up to the age of 16 weeks, none of the babies in either group showed any neurologic impairment when neurologic development was assessed using the Gessel infant development schedule. However, further follow-up is required before any conclusions can be drawn regarding the long-term outcome of the babies. In group I, the mean ("S.D.) NRBC per 100 WBC was 16.5 ("6.4), range 3–25. This was
0.7797
significantly higher than the values in group II, in which mean ("S.D.) was 8.6 ("7.01), with a range of 1–26 (P-0.001). Other hematological parameters were also estimated in umbilical venous blood and the hemoglobin (Hb) level, packed cell volume (PCV) and red blood cell (RBC) count were significantly higher in the group I neonates (Table 3). The NRBC per 100 WBC count correlated well with Apgar score and umbilical arterial pH. The correlation coefficient (r) between NRBC per 100 WBC and Apgar score at 1 min was y0.50 (P0.001) while that between NRBC per 100 WBC count and pH was y0.48 (P-0.001). There was also a statistically significant correlation of NRBC per 100 WBC count in neonates of group I and
Table 2 Comparison of neonatal outcomes of group I and II Parameter
Group I (ns26)
Group II (ns49)
P-value
Meconium staining of liquor
15 (57.7%)
12 (24.5%)
NICU admission
20 (76.9%)
2 (4.1%)
Presence of HIE in newborn
10 (38.4%)
0 (0%)
2 (7.7%)
0 (0%)
Ps0.009, O.R. 4.2 (C.I. 1.4–13.3) P-0.001, O.R. 78.3 (C.I. 12.5–288.9) P-0.001, O.R. not calculable 0.117
Early neonatal death
270
B. Ghosh et al. / International Journal of Gynecology and Obstetrics 81 (2003) 267–271
Table 3 Hematological parameters in umbilical venous blood of neonates in group I and II Hematological parameters
Group I (ns26) mean"S.D.
Group II (ns29) mean"S.D.
P-value
NRBCy100 WBC WBC count=103 ymm3 Hb (gmydl) RBC count (=106 ymm3) PCV (%) MCH (pg) MCHC (g%)
16.5"6.4 13.966"3.05 15.7"0.88 4.9"0.30 51.5"3.7 31.6"1.4 30.6"2.0
8.6"7.01 12.804"2.80 14.6"1.11 4.7"0.46 47.4"4.18 31.4"3.7 30.9"2.6
0.001 0.102 0.000 0.005 0.001 0.721 0.597
MCHC levels (rsy0.49, Ps0.012) as well as development of HIE (rs2.2, Ps0.037). The neonates in group II (non-asphyxiated group) demonstrated significant correlation between NRBC per 100 WBC count and period of gestation (rs y0.29, Ps0.037), birth weight of babies (rs y0.51, P-0.001) and presence of PIH andyor IUGR (ts2.66, Ps0.025). There was no significant correlation of NRBC count with mode of delivery, duration of labor or the presence of meconium in either group. 4. Discussion Nucleated red blood cells are commonly seen in the cord blood of healthy newborns at birth. In term non-asphyxiated newborns, the number of nucleated red blood cells is variable but is only rarely higher than 10 w2,4,8,9x. In our study the results in non-asphyxiated newborns (group II) are in keeping with previous observations w2,4,8,9x. Previous investigators have suggested that nucleated red blood cells increase in response to an asphyxial event w6,9–11x. Also in the present study, a statistically significant correlation was demonstrated between NRBC per 100 WBC count and presence of IUGR andyor PIH (evidence of chronic antepartum hypoxia), Apgar score at 1 min of birth and the umbilical arterial pH value at birth (evidence of acute intrapartum hypoxia). Data from our study did not indicate any significant correlation between NRBC counts and the mode of delivery (vaginal delivery vs. cesarean section), as well as duration of labor. Similar findings have been reported previously w9,11x.
In the past, studies have shown higher nucleated RBC levels in neonates with evidence of neurological impairment w6,10,12,13x. The findings in the present study are consistent with previous studies, and a significantly higher NRBC per 100 WBC count was found in those who developed hypoxic ischemic encephalopathy in the early neonatal period. To conclude, estimating the number of nucleated RBC per 100 WBC in umbilical venous sample of newborns is a simple test, the sample being obtained non-invasively from an otherwise discarded specimen and analyzed by personnel on equipment readily available in most hospital laboratories. The level of nucleated RBC per 100 WBC correlates both with acute intrapartum asphyxia as well as chronic antepartum hypoxia and can be used as a reliable index of early neonatal outcome. The study followed infants to 16 weeks of age and may not be able to state conclusions regarding chronic outcomes. References w1x Low JA. The role of blood gas and acid-base assessment in the diagnosis of intrapartum fetal asphyxia. Am J Obstet Gynecol 1988;159:1235 –1240. w2x Gilstrap LC, Kenneth J, Leveno Burris J, William ML, Little BB. Diagnosis of birth asphyxia on the basis of fetal pH, Apgar score and newborn cerebral dysfunction. Am J Obstet Gynecol 1989;161:825 –830. w3x ACOG Committee Opinion: Committee on Obstetric Practice. Number 138. Utility of umbilical cord blood acid-base assessment. Int J Gynecol Obstet 1994;45:303. w4x Hanlon-Lundberg KM, Kirby RS, Gandhi S, Broekhuizen FF. Nucleated red blood cells in cord blood of singleton term neonates. Am J Obstet Gynecol 1997;176:1149 –1156.
B. Ghosh et al. / International Journal of Gynecology and Obstetrics 81 (2003) 267–271 w5x Green DW, Mimouni F. Nucleated erythrocytes in healthy and in infants of diabetic mothers. J Pediatr 1990;116:129 –131. w6x Philip AGS, Tito AM. Increased nucleated red blood cell counts in small for gestational age infants with very low birth weight. Am J Dis Child 1989;143:164 –169. w7x Snijders RJM, Abbas A, Melby O, Ireland RM, Nicolaides KH. Fetal plasma erythropoietin concentration in severe growth retardation. Am J Obstet Gynecol 1993;168:615 –619. w8x Phelan JP, Ahn MO, Korst LM, Martin GI. Nucleated red blood cells: a marker for fetal asphyxia? Am J Obstet Gynecol 1995;173:1380 –1384. w9x Hanlon-Lundberg KM, Kirby RS. Nucleated red blood cells as a marker of acidemia in term neonates. Am J Obstet Gynecol 1999;181:196 –201.
271
w10x Saracouglu F, Sahin I, Eser E, Gol K, Turkkani B. Nucleated red blood cells as a marker in acute and chronic fetal asphyxia. Int J Gynecol Obstet 2000;71:113 –118. w11x Korst LM, Phelan JP, Ahn MO, Martin GI. Nucleated red blood cells: an update on the marker for fetal asphyxia. Am J Obstet Gynecol 1996;175:843 –846. w12x Thilaganathan B, Athanasiou S, Ozmen S, Creighton S, Watson NR, Nicholaides KH. Umbilical cord blood erythroblast count as an index of intrauterine hypoxia. Arch Dis Child 1994;70:F192 –F194. w13x Blackwell SC, Refuerzo JS, Wolfe HM, Hassan SS, Berry SM, Sokoi RJ, et al. The relationship between nucleated red blood cell counts and early onset neonatal seizures. Am J Obstet Gynecol 2000;182:1452 –1457.