ABO incompatibility and RhIG immunoprophylaxis protect against non-D alloimmunization by pregnancy

Transfusion. 2018 Jul;58(7):1611-1617. doi: 10.1111/trf.14606. Epub 2018 Apr 6.


Background: Hemolytic disease of the fetus and newborn (HDFN) is caused by maternal antibodies against fetal red blood cell antigens, most often anti-D, -K, or -c. ABO incompatibility between mother and child and anti-D immunoprophylaxis (RhIG) are known to reduce the risk of D immunization and subsequent HDFN. However, no immunoprophylaxis has been developed to prevent non-D immunizations.

Study design and methods: We evaluated whether ABO incompatibility has a preventive effect on formation of non-D alloantibodies, by performing a case-control study including pregnant women with newly detected non-D antibodies, identified within a nationwide data set, immunized during their first pregnancy and/or delivery. Subsequently, we assessed a possible protective effect of RhIG in a subgroup with non-Rh antibodies only. The proportions of previous ABO incompatibility and of RhIG administrations of these women were compared to the known rate of 19.4% ABO incompatibility and 9.9% RhIG administrations (D- women carrying a D+ child) in the general population of pregnant women.

Results: A total of 11.9% of the 232 included immunized women had a possible ABO incompatibility in their first pregnancy (vs. expected 19.4%; 95% confidence interval [CI], 7.3-18.8; p = 0.036). Furthermore, 1.0% women with non-Rh antibodies were D-, delivered a D+ child, and had therefore received RhIG, whereas 9.9% was expected (95% CI, 0.18-5.50; p = 0.003).

Conclusion: We found that ABO incompatibility and RhIG reduce the risks not only for D, but also for non-Rh immunizations, suggesting that antibody-mediated immune suppression in this condition is not antigen specific.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ABO Blood-Group System / immunology*
  • Adult
  • Blood Group Incompatibility / immunology*
  • Case-Control Studies
  • Female
  • Humans
  • Isoantibodies / immunology*
  • Pregnancy
  • Rho(D) Immune Globulin / immunology


  • ABO Blood-Group System
  • Isoantibodies
  • Rho(D) Immune Globulin