Objective: To study fetal erythroblasts (FE) from maternal peripheral blood for the diagnosis of fetal aneuploidies.
Methods: FE expressing the glycophorin A(GPA) were isolated from 13 pregnant women with male fetus (8-14 w) by fluorescence-activated cell sorting(FACS), FE were identified by oligonucleotide primed in situ labelling (PRINS) with Y centromeric satellite DNA primer. The concentration of pregnancy-associated plasma protein A (PAPP-A) was measured by enzyme-labelled immunosorbent assay (ELISA) in serum samples of 41 normal pregnant women (8-14 w). In 5 pregnant women suspicious of fetal Down's syndrome (10-13 w) the serum and FE were examined by PAPP-A, GPA/FACS and PRINS with 21 chromosome centrometric primer.
Results: Detection of flow sorted FE from 13 pregnant women by Y primer showed 14.5% of GPA positive signal. There was no difference in serum level of PAPP-A between 5 pregnant women and 41 normal controls, and all GPA positive cell nuclei of the 5 cases displayed two signals with 21 chromosome.
Conclusion: Measurement of fetal erythroblasts from maternal blood for the diagnosis of genetic fetal aneuploidies is a promising non-invasive, rapid and reliable technique.