A correlation between severe haemolytic disease of the fetus and newborn and maternal ABO blood group

Abstract

Objective: To analyse anti-D quantification levels and frequency of intrauterine transfusion (IUT), per maternal ABO blood group.

Background: Maternally derived red cell allo-antibodies can target fetal red cell antigens in utero leading to haemolytic disease and fetal anaemia. When a clinically significant allo-antibody is formed the priority is ascertaining the risk to the fetus and maternal ABO blood groups are not considered relevant.

Materials and methods: This was a 10-year retrospective, observational study carried out on women referred for anti-D quantification (n = 1106), and women whose fetuses required an IUT to treat fetal anaemia (n = 62) due to anti-D, in the Republic of Ireland.

Results: Relative to the overall incidence of RhD allo-immunisation by blood group, women of blood group A were more likely to require IUT compared with those who were blood group O (P = 0.002).

Conclusion: It is known that ABO feto-maternal compatibility can influence the incidence and level of red cell allo-antibodies in pregnancy; however, it does not account for the significantly high rate of severe haemolytic disease requiring IUT seen in blood group A women.

Keywords: ABO blood group; haemolytic disease; intrauterine transfusion.