A further decrease was observed in several studies investigating routine antenatal administration of anti-D Ig, primarily to prevent immunisation from undetected FMHs during the last trimester of pregnancy.10–12 But, even if postnatal and antenatal prophylaxis are combined, 0.1–0.3% of women at risk still develop RhD antibodies,13,14 contributing to a significant number of new RhD immunisations and cases of HDFN. This evidence concerns the gene RHD and rheumatic heart disease.