Human Reproduction vol.9 no.6 pp. 1184-1189, 1994 Trophoblasts circulating in maternal blood as candidates for prenatal genetic evaluation

3To whom correspondence should be addressed Trophoblasts have been detected in uterine venous blood, lung parenchyma and maternal blood in the first trimester. Their dilution within maternal leukocytes has been recently estimated to be l:10~6. The objectives of this study were to enrich peripheral maternal blood preparations for trophoblast cells, to isolate trophoblasts from the enriched preparation by highly specific markers and to assess fetal cell total number of chromosomal copies by fluorescence in-situ hybridization (FISH). Negative and positive selections for trophoblasts were performed. To assess the efficacy of the enrichment methods, a model mimicking the in-vivo conditions was established. Purified first trimester trophoblasts were prepared from first trimester placentas and were mixed with leukocytes from non-pregnant women in various concentrations. Magneti