Improved detection of fetal cells from maternal blood with polymerase chain reaction.

Abstract

The objective was to test the reliability of new deoxyribonucleic acid primers that have previously been used very efficiently by this laboratory with amniolysate samples to amplify a 248 bp Y-specific, repeated sequence from maternal blood during pregnancy. Blood samples were obtained from 50 women during weeks 11 and 16 of pregnancy and were analyzed for the presence of the Y chromosome-specific sequences. Y-specific fragments were identified in 19 of 24 (79.2%) women after one complete amplification. A second amplification of these samples negative for Y-specific fragments revealed three additional samples positive for the Y chromosome-specific fragment. Only two male fetuses remained unidentified. Overall, 91.7% male fetuses and 96% of all fetuses (48/50) in these women were correctly identified. The primers described in this study provide an additional or alternative tool for the determination, by means of the polymerase chain reaction, of Y chromosome-bearing cells in maternal circulation.