A minimally invasive prenatal diagnosis technique for the collection of transcervical cells

Transcervical cell (TCC) samples were retrieved between 6 and 15 weeks of pregnancy by a simple and rapid method of aspiration. The presence of fetal cells was investigated by polymerase chain reaction (PCR) assays for the amplification of DNA sequences from chromosomes X and Y, and of polymorphic short tandem repeats (STR) specific for chromosomes 21 and 18. As judged by the detection of Y-derived PCR products, fetal cells were present in 68% of TCC samples collected from mothers with male fetuses. Paternally inherited fetal STR markers were detected in 29.6% of the tested TCC samples, while a further 44% of samples were non-informative, as the fetus had inherited markers similar to those of the mother.