Operator experience and sample quality in genetic amniocentesis

We sought to relate the frequency of maternal cell contamination in amniotic fluid samples that were submitted to a single laboratory for cytogenetic analysis to the experience and training of the physician who performed the amniocentesis. We reviewed the database of a single cytogenetics laboratory to compare the number of amniocenteses that were performed annually per physician to the rate of maternal cell contamination in genetic amniocentesis samples. Only samples that resulted in a 46 XY male karyotype were studied so that maternal cell contamination could be identified as having occurred when the karyotype revealed ≥1 cell with 2 X chromosomes. Samples were categorized as being submitted by a physician who submitted ≥50 or more samples annually versus