RHD and fetal erythroblastosis: Clinical signs were highly suggestive of HDFN in 5.8% of RhD-negative women, as compared to 0.2% in RhD-positive women (<i>P</i><.0001).<h4>Conclusion</h4>Our study identifies that RhD-negative women experience a two-fold increased odds of APO, most likely due to HDFN.