Prevalence of Alloimmunizations in Moroccan Pregnant Women

Abstract

Introduction: Erythrocyte fetomaternal incompatibility is defined by the binding of erythrocyte alloantibodies of a pregnant woman to fetal antigens, inherited from the father. Alloantibodies are produced by the immune system after prior contact with these same antigens during transfusion, transplant or previous pregnancy. In Morocco, data concerning fetomaternal incompatibilities are insufficient despite the severe cases of hemolytic disease in newborns recorded. Our aim is to determine the prevalence of anti-erythrocytes alloimmunizations in Moroccan pregnant women as well as the frequencies of alloantibody specificities. Patients and Methods: A population of parturients with no obstetrical history was randomly recruited to the Blood Bank of Kenitra. A second population was formed by pregnant women referred to the Regional Blood Transfusion Center of Rabat for reasons of obstetrical and/or immunohaematological history. The tests were carried out using the gel cards and 2 panels of 11 red blood cells. Antibody titration was performed by indirect Coombs technique. Results: Immunohematological tests and analysis of clinical-biological data made it possible to detect and confirm alloimmunization in 16 RhD negative and positive women. The prevalence of alloimmunization in RhD negative women is 2.46 % and the prevalence of alloimmunization in both RhD-/+ parturients was 1,06 %. In parturients with an obstetric history, the frequencies of alloantibodies are respectively 35.48% (11/31) and 100% (3/3) directed against 7 antigenic specificities: D, C, E, c, e, Jka and s. None of the parturients had received timely anti-D prophylaxis or prenatal RhD genotyping. Conclusion: The discussion of our results highlights the problem of the management of pregnant women at risk of alloimmunization, putting Morocco in front of a challenge of setting up a health policy, including above all the training of health professionals and the accessibility at the national level to the biological examinations necessary for the follow-up of the pregnant women to reduce the prevalence of the HDFN.