Nucleated Red Blood Cells in Term Fetuses: Reference Values Using an Automated Analyzer

Abstract

Background: Nucleated red blood cells (NRBCs) are present in small numbers in the cord blood of healthy fetuses at birth. Acute and chronic stimuli, such as fetal hypoxia, cause increased circulating levels of NRBCs. Manual counting is presently the only way to quantify NRBCs, but it is time-consuming and inaccurate. Recently, automated approaches have been developed in order to quantify NRBCs. Objectives: Our aim was to compare manual vs. automated NRBC counting and derive reference values in umbilical cord blood samples from healthy term fetuses. Methods: We analyzed blood samples from 131 healthy term fetuses by the automated approach and calculated reference values of NRBC counts as percentiles. To compare automated NRBC count with manual count we obtained umbilical cord blood samples from 50 further fetuses. Results: Significant positive correlation was obtained between the two methods (r² = 0.988, Bland-Altman plot mean difference NRBCs/100 WBC: –0.590). The median for NRBCs/100 WBC was 3.05 (range 0–11.6) and the median for absolute NRBC counts ×10⁹/l was 0.39 (range 0–1.8). Conclusions: We demonstrate that values obtained with the automated NRBC counting method are comparable to those obtained with the microscopic manual evaluation and give reference values for umbilical cord NRBCs at term that can be used in clinical practice.

Novel DNA methylation profiles associated with key gene regulation and transcription pathways in blood and placenta of growth-restricted neonates

“…58 However, at term nucleated red blood cells comprise a small percentage of total cell number (3 per 100 wbcs), which limits their influence on the methylation of cells from cord blood. 59 Furthermore, according to the Marmal-aid data set, we showed a similar pattern of DMPs in areas normally unmethylated and across cord blood cell types. Differences in cell type that might exist at term between FGR and AGA are unlikely to play a significant role in observed DMPs.…”

Reference Ranges for Blood Concentrations of Nucleated Red Blood Cells in Neonates

“…This is the same conclusion reached by Perrone et al [1] . Rolfo et al [3] found no difference between automated and manual NRBC counts of 50 neonatal samples. Similarly, Gulati et al [10] studied 460 samples of adult blood, and generally found agreement between automated and manual methods.…”

“…Nucleated red blood cells (NRBC) are often observed in the blood of term and preterm neonates [1][2][3] . A high concentration of NRBC at birth has been associated with an increased risk of developing intraventricular hemor-290 rhage (IVH) and/or retinopathy of prematurity (ROP) [4,5] .…”

Massively Elevated Nucleated Red Blood Cells and Cerebral or Pulmonary Hemorrhage in Severely Growth-Restricted Infants – Is There More than Coincidence?

“…2 ). Based on the upper limit of normal NRBC values (above the 97.5th percentile) published in the literature [6,7] , 5/6 (83%) group 1 patients compared with 3/14 (21%) group 2 patients had NRBC counts above the upper reference limit ( fig. 3 ).…”