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

OBJECTIVE: 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. STUDY DESIGN: 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. RESULTS: 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. CONCLUSIONS: 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. (AM J OBSTET GYNECOL 1994;170:952-5.) © 1994, Mosby, Inc.. All rights reserved.