Abstract
We wished to determine the time of pregnancy at which optimal numbers of nucleated red blood cells (NRBC) are present in maternal blood. Because 30% of the NRBC in maternal blood are fetal, there are implications for prenatal screening and diagnosis. Samples of whole blood were collected from each of 225 women at various times during pregnancy. The samples were processed by charge flow separation (CFS), the NRBC enumerated, and the numbers compared on a week-to-week basis. To quantify the relationship between week of pregnancy and actual and log-transformed numbers of NRBC recovered, Pearson product moment and Spearman correlation coefficient were estimated for each of four CFS instruments and for the four instruments combined. When the data were analyzed, we found no relationship between stage of pregnancy and numbers of NRBC recovered. Even after logarithmic transformation, variability among the women, estimated by standard deviation, was large and relatively stable across the different stages of pregnancy. The number of NRBC recoverable by CFS appears to be constant between 7 and 25 weeks.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 26 August 1998 / Accepted: 26 October 1998
Rights and permissions
About this article
Cite this article
Shulman, L., Phillips, O., Tolley, E. et al. Frequency of nucleated red blood cells in maternal blood during the different gestational ages. Hum Genet 103, 723–726 (1998). https://doi.org/10.1007/s004390050898
Issue Date:
DOI: https://doi.org/10.1007/s004390050898