IMPROVED DETECTION OF FETAL CELLS FROM MATERNAL BLOOD WITH POLYMERASECHAIN-REACTION

OBJECTIVE: The objective was to test the reliability of new deoxyribon ucleic acid primers that have previously been used very efficiently by this laboratory with amniolysate samples to amplify a 248 bp Y-specif ic, repeated sequence from maternal blood during pregnancy. STUDY DESI GN: Blood samples were obtained from 50 women during weeks 11 and 16 o f pregnancy and were analyzed for the presence of the Y chromosome-spe cific sequences. RESULTS: Y-specific fragments were identified in 19 o f 24 (79.2%) women after one complete amplification. A second amplific ation of these samples negative for Y-specific fragments revealed thre e additional samples positive for the Y chromosome-specific fragment. Only two male fetuses remained unidentified. Overall, 91.7% male fetus es and 96% of all fetuses (48/50) in these women were correctly identi fied. CONCLUSIONS: The primers described in this study provide an addi tional or alternative tool for the determination, by means of the poly merase chain reaction, of Y chromosome-bearing cells in maternal circu lation.