Risk factors for the presence of non‐rhesus D red blood cell antibodies in pregnancy*

Abstract

Objective To identify risk factors for the presence of non-rhesus D (RhD) red blood cell (RBC) antibodies in pregnancy. To generate evidence for subgroup RBC antibody screening and for primary prevention by extended matching of transfusions in women <45 years.Design Case-control study.Setting Nationwide evaluation of screening programme for non-RhD RBC antibodies. Methods Data collection from the medical records and/or from the respondents by a structured phone interview.Main outcome measures Significant risk factors for non-RhD immunisation in multivariate analysis.Results Significant independent risk factors: history of RBC transfusion (OR 16.7;), parity (para-1 versus para-0: OR 1.3; 95% CI: 1.0-1.7; para-2 versus para-0: OR 1.4; 95% CI: 1.0-2.0; para >2 versus para-0: OR 3.2; 95% CI: 1.8-5.8), haematological disease (OR 2.1; 95% CI: 1.0-4.2), history of major surgery (OR 1.4; 95% CI: 1.1-1.8). For the clinically most important antibodies, anti-K, anti-c and other Rh-nonDantibodies RBC transfusion was the most important risk factor, especially for anti-K (OR 96.4; 95%-CI: 56.6-164.1); 83% of the K-sensitised women had a history of RBC transfusion. Pregnancyrelated risk factors were a prior male child (OR 1.7; 95% CI: 1.2-2.3) and caesarean section (OR 1.7; 95% CI: 1.1-2.7).Conclusions RBC transfusion is by far the most important independent risk factor for non-RhD immunisation in pregnancy, followed by parity, major surgery and haematological disease. Pregnancy-related risk factors are a prior male child and caesarean section. Subgroup screening for RBC antibodies, with exclusion of RhD-positive para-0 without clinical risk factors, is to be considered. This approach will be equally sensitive in detecting severe Haemolytic Disease of the Fetus and Newborn compared with the present RBC antibody screening programme without preselection. Primary prevention by extending preventive matching of transfusions in women younger than 45 will prevent more than 50% of pregnancy immunisations.

Alloimmunisation during pregnancy in Greece: need for nationwide HDFN prevention programme

“…Maternal age did not seem to contribute to alloimmunisation, while multiparity and transfusion history showed a significant correlation. This is in accordance with the results of Koelewijn et al ., () who found that RBC transfusion was the most important independent risk factor for non‐RhD immunisation in pregnancy. Nevertheless, no blood transfusion scientific society recommends additional matching for women of fertile age besides pre‐emptive K antigen matching.…”

Triggers and appropriateness of red blood cell transfusions in the postpartum patient–a retrospective audit

“…The drawbacks of inappropriate transfusions may be considerable. In a large survey for non‐Rhesus D red cell antibodies in pregnant women, previous transfusions were the major factor associated with irregular antibodies, much stronger than previous pregnancies [17]. From an ongoing study on transfusion triggers in postpartum patients (WOMB study, NCT00335023) with quality of life (fatigue) as a primary end‐point, more insight can be gained concerning the optimal threshold for this selected population [18].…”

The Outcome of Hemolytic Disease of the Fetus and Newborn Caused by Anti-Rh17 Antibody: Analysis of Three Cases and Review of the Literature

“…Most of the authors recommend that transfusion therapy in women younger than 50 years of age should be K, Rhc–, and RhE– compatible [19, 20]. In our presented Case 1, D-- phenotype was not tested before transfusion.…”

“…Regarding RBC alloimmunization by transfusion, it is advisable that all women of childbearing age are given RBCs compatible with Rh and Kell phenotype to prevent Rhc, Kell, RhE, RhC, and Rh17 immunizations [19, 20].…”