Tehran University Medical Journal

Background: The presence of increased numbers of nucleated red blood cell (NRBC) in the umbilical cord blood has been associated with states of relative hypoxia. Nucleated red blood cell counts are a potentially useful tool in estimating the degree and timing of intrauterine hypoxia. This may have important implication in determining causality in case of compromised infant. Cord blood NRBC counts may be obtained noninvasively from an otherwise discarded specimen and analyzed by personnel on equipment readily available in most hospital laboratories. Since the aim of monitoring of fetal heart is early diagnosis of hypoxia, we studied the relationship between abnormal fetal heart rate with the number of nucleated red blood cells (NRBC) in the umbilical cord blood.

Methods: We performed this research at Hazrat Zeynab Hospital on 130 full-term newborns (65 cases of fetal distress and 65 normal cases) between July 2005 and July 2006. The NRBC counts of newborns with abnormal fetal heart rate were compared with those of normal newborns and correlations with other parameters including Apgar score, hemoglobin level, condition of newborns in the first 24 hours of the birth and birth weight.

Results: The mean NRBC count in the fetal distress group was 9.45 ± 8.75 and that of the normal group was 9.17 ± 8.76 per 100 white cells (p=0.89). The mean duration between diagnosis of fetal distress to birth was equal to 1.2± 0.77 hours. Furthermore, there was no meaningful correlation between number of NRBC and Apgar score, hemoglobin, birth weight and condition of newborns in the first 24 hours.

Conclusion: If the fetus is born a short time after the diagnosis of distress with no risk factors for hypoxia, the NRBC count for cord blood is not elevated.

Background: Previous studies have suggested the presence of a relationship between the increase of NRBC and the duration and intensity of asphyxia. The purpose of this study was to evaluate the relationship of fetal heart rate pattern and the number of NRBC's in umbilical cord blood sample at birth.

Methods: We enrolled 322 pregnant women with healthy, term fetuses who referred to Mirza Kouchak Khan Hospital for pregnancy termination in 2005 in a case-control study. All patients underwent continuous FHR monitoring and based on their FHR pattern, they were divided into two groups with normal FHR pattern and at least one abnormality in FHR pattern (including absence of beat to beat variability absence of proper acceleration and early, late, variable and prolonged deceleration). Samples of umbilical cord blood were evaluated for NRBC count and pH immediately after birth. The variables were compared in these two groups.

Results: The mean NRBC count was significantly higher in patients with any kind of deceleration (late, variable, early or prolonged) in comparison with controls (respectively 11.88±4.406, 8.32±4.64, 10.58±5.366, and 4.11±4.913 vs. 0.93±1.790 in controls). Furthermore the mean NRBC count was significantly higher in patients with absence of acceleration or beat to beat variability (10.73±5.07 and 13.73±3.58 vs. 1.47±2.50). There was a negative correlation between 5^th minute Apgar score and umbilical cord blood sample with mean NRBC count of umbilical cord blood sample.

Conclusion: Any abnormality in FHR pattern is associated with a significant increase in mean NRBC count of umbilical cord blood sample. There is also a significant relationship between the 5^th minute Apgar score and umbilical cord blood sample pH, and mean NRBC count in umbilical cord blood sample.