Evaluating the culture of fetal erythroblasts from maternal blood for non-invasive prenatal diagnosis.

Fetal erythroblasts circulating in maternal blood are important candidate cells for non-invasive prenatal diagnosis. We have cultured erythroblasts from 16 maternal blood samples, both with and without prior enrichment by magnetic activated cell sorting (MACS), in a semi-solid medium containing growth factors. Individual colonies were examined by PCR with sex chromosome-specific primers and microsatellite marker primers. No conclusive Y-chromosome specific amplification could be demonstrated in any of the 16 cases, even when the mother was confirmed to be carrying a male fetus. All colonies tested by microsatellite marker PCR were of maternal origin. Our results suggest that the probability of obtaining fetal colonies from fetal erythroblasts circulating in maternal blood is very low and that approaches for culturing fetal erythroblasts in vitro cannot yet be used reliably for prenatal diagnosis using current methods for fetal cell enrichment.