Enrichment and identification of fetal trophoblast cells from first trimester maternal cervical lavage and uterine blood specimens

First trimester prenatal diagnosis of fetal ancuploidies is an active area of research despite years of disappointing data employing maternal peripher al blood samples. To remedy this situation we have investigated other first trimester maternal specimens attempting to find a consistent fetal cell so urce. Using our previously established positive enrichment procedure along with a commercially available depletion method, fetal trophoblast cells wer e identified employing immunocytochemistry using an antibody cocktail or by using mRNA in-situ hybridization employing a cocktail of trophoblast speci fic robes. Fetal origin of p positively identified cells was verified using interphase fluorescent in-situ hybridization (FISH) for X and Y-chromosome s. Artificial model systems were established that indicated yields of troph oblast cells and allowed the enrichment procedure to be optimized for minim al losses from maternal specimens. We demonstrate herein that blood drawn f rom maternal vessels near the placental implantation site to be the most co nsistent source of fetal cells from any first trimester maternal specimen d escribed to date. In addition, a high yield of multinucleated syncytiotroph oblast cells was obtained using a cell depletion strategy to enrich the tar get cells. The safety of the procedure or even the clinical utility of bloo d drawn from maternal vessels near the placental implantation site is yet t o be demonstrated. (C) 2001 Harcourt Publishers Ltd.