[Fetal nucleated erythrocytes in the peripheral circulation of pregnant women as a noninvasive method of fetal sex determination]. / Fetální jaderné erytrocyty cirkulující v periferii gravidních zen jako neinvazivní zdroj detekce pohlaví fetu.

OBJECTIVE: Determination of the sex of the foetus from enriched nuclear red blood cells (NRBC) circulating in maternal blood during pregnancy. METHODS: NRBC were enriched from 13-28 ml peripheral blood of 32 pregnant women using double MACS procedure. NRBCs were enriched by magnetic activated cell sorting using anti-CD71 (transferrin receptor) monoclonal antibodies. Unwanted leukocytes were depleted using monoclonal antibodies against CD14 and CD45. The sex of the foetus was analysed by using dual-colour FISH with X and Y specific probes. The experimental results obtained from the noninvasive procedure were compared to karyotype obtained from amniocentesis or chorionic villus sampling. RESULTS: In 15 out of 17 male foetuses we could identify one X and one Y signal. In another 15 pregnant women carrying female foetuses two X signals were observed. CONCLUSION: NRBC circulating in blood of pregnant women can be used as an alternative source for determination of the sex of the foetus with a risk of false negative results (2/17, 12%). The problem of false negative results can be solved by using more sophisticated methods of enrichment and preparedness of the slides for FISH analysis.