Objectives: To investigate the feasibility of using single fetal nucleated erythroblasts (FNRBCs) and free DNA in maternal blood for non-invasive prenatal diagnosis.
Methods: Single FNRBCs were isolated from 51 of 116 samples of maternal blood analyzed by micromanipulation after density gradient centrifugation. Furthermore, the nested polymerase chain reaction (PCR) method was used to amplify the SRY gene of single FNRBCs. Primer extension pre-amplification and nested PCR were used to amplify the SRY gene of the plasma DNA extracted from 65 samples of maternal blood.
Results: The detection rate of single FNRBCs was 90.20% (46/51). The concordance rates between real fetal sex and sex determined by amplification of the SRY gene from single cells and from free DNA analysis were 82.61% (38/46) and 90.77% (59/65), respectively.
Conclusions: Single nucleated erythroblasts and free DNA in maternal blood are of fetal origin and can be valuable fetal material sources for non-invasive prenatal diagnosis.