MATERNAL CONTAMINATION OF AMNIOTIC-FLUID DEMONSTRATED BY DNA ANALYSIS

DNA from 16 sets of samples comprising DNA from uncultured amniotic fl uid cells, cultured amniotic fluid cells, fetal tissue, and maternal b lood was analysed by the polymerase chain reaction (PCR) with AC-repea t primers. The analysis was performed to investigate the presence of c ontaminating maternal cells in amniotic fluid which would affect the r eliability of DNA studies for prenatal diagnosis. In three sets, mater nal contamination of uncultured amniotic fluid cells was detected. In one of the three sets, maternal contamination was present in both uncu ltured and cultured amniotic fluid cells. The use of amniotic fluid ce lls as a source of DNA for prenatal diagnosis should be limited to cas es where the purity of the DNA can be demonstrated prior to the diagno stic test being performed. This limitation in the use of amniotic flui d DNA also extends to other forms of diagnosis relying on the purity o f amniotic fluid samples, particularly the new in situ hybridization m ethods currently being developed.