Frequency and characterization of known and novel RHD variant alleles in 37 782 Dutch D‐negative pregnant women

To guide anti-D prophylaxis, Dutch D- pregnant women are offered a quantitative fetal-RHD-genotyping assay to determine the RHD status of their fetus. This allowed us to determine the frequency of different maternal RHD variants in 37 782 serologically D- pregnant women. A variant allele is present in at least 0·96% of Dutch D- pregnant women The D- serology could be confirmed after further serological testing in only 54% of these women, which...