Red cell fetomaternal allo immunization

BACKGROUND: Fetomaternal Rhesus incompatibility is a medical condition that affects the pregnant woman [of blood group (A, B, AB, O) and a negative Rhesus] and the foetus (of positive Rhesus). The objective of this study is to determine the prevalence and to present the clinical characteristics of fetomaternal Rhesus incompatibility in a tertiary care hospital. METHODS: The authors conducted a retrospective cross-sectional study and 37 participants were recorded during the study period of 4 years...

BACKGROUND AND OBJECTIVES: Alloantibodies against red-blood-cell (RBC) antigens often coincide with alloantibodies against leucocytes and platelets and sometimes with autoantibodies towards various antigens. Chimerism may be one of the factors responsible for the combination of allo- and autoantibodies. Women with alloantibodies against RBC antigens causing haemolytic disease of the fetus and neonate may need to receive intrauterine transfusions. These transfusions increase not only maternal antibody formation but also fetomaternal bleeding and may enhance fetal chimerism...

Immuno-hematological follow up of pregnant women. The goal of immuno-hematological follow-up during pregnancy is to organize maternal transfusion safety and optimal management of fetal and neonatal hemolytic disease, that may result from maternal immunization. This follow-up relies on scheduled antibodies detection following regulation. Since May 2017 the refund by social security of the fetal RHD genotyping analysis on maternal plasma, it is possible to limit prophylaxis of allo-immunization to RhD-negative women with a RhD positive fetus...

Feto-maternal red cell alloimmunization is defined by the presence in a pregnant woman of alloantibodies directed against blood group antigens present on the red blood cells of the fetus and inherited from the father. It arises from the immune response to a first contact to these same antigens during a prior transfusion, transplant or pregnancy. The placental transfer and the fixation of the antibodies on the fetal red cells antigenic targets lead to a haemolysis in the fetus and the newborn. The resulting haemolytic disease can show different clinical forms, from a mild anaemia with neonatal hyperbilirubinemia to a major fetal damage with stillbirth caused by hydrops fetalis...

RhD prophylaxis concerns RhD negative women, who are non-sensitized against D antigen during and at the end of their pregnancy with a RhD positive child. RhD prophylaxis includes targeted prophylaxis (prevention of anti-D immunization after feto-maternal hemorrhage (FMH) induced by prenatal events and delivery) and routine antenatal D prophylaxis (prevention of anti-D immunization resulting from spontaneous FMH in the last trimester of pregnancy). Targeted prophylaxis should be applied regardless of the gestational age and a dose of 100microg anti-D is usually enough (200microg is the lowest dosage currently available in France)...

At present, rhesus prophylaxis concerns RhD negative pregnant women, even though 30 to 40% of them are bearing a RhD negative child. Knowing the RhD fetal genotype could change this quite irrational practice of prophylaxis (exposing many more women than needed to blood derived products) without reducing its efficacy. RhD fetal genotype determined on amniotic fluid has an excellent sensitivity. Presence of silent D genes slightly impairs its specificity which remains acceptable. However women have to be informed of possible false positives...

OBJECTIVE: To provide guidelines on use of anti-D prophylaxis to optimize prevention of rhesus (Rh) alloimmunization in Canadian women. OUTCOMES: Decreased incidence of Rh alloimmunization and minimized practice variation with regards to immunoprophylaxis strategies. EVIDENCE: The Cochrane Library and MEDLINE were searched for English-language articles from 1968 to 2001, relating to the prevention of Rh alloimmunization. Search terms included: Rho(D) immune globulin, Rh iso- or allo-immunization, anti-D, anti-Rh, WinRho, Rhogam, and pregnancy...

The A.V.I.S. Blood Transfusion Center of Turin performs the screening of foetomaternal allo-immunizations for the S. Anna Hospital of Turin. This hospital includes 3 hospital departments and 3 obstetrical and gynaecological university departments. The number of births in one year is roughly 13.000, i.e. 50 mother-baby couples, are tested every day. The identification system and the sampling process are described. The program used on the Groupamatic system includes: 1.) First run: Blood typing of mother blood with screening of alloantibodies...