An automated magnetic capture hybridization (MCH) method for the extraction and enrichment of fetal RHD specific DNA fragments from maternal plasma was developed using plasma from 1000 D-negative pregnant women. A real time PCR protocol for RHD exon 7 was applied. MCH was compared with the QIAamp DSP Virus Kit (QIAamp) as a reference. Compared with the QIAamp method, the percentage of fetal DNA increased from 2.86% to 4.83% (p<0.05, n=8). The 95% detection limit of MCH was determined at 286 pg/ml (43 geg/ml) compared with 138 pg/ml (21 geq/ml) for the QIAamp DSP Virus Kit.