Volume 116, Issue 5 p. 655-664

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

JM Koelewijn

JM Koelewijn

Sanquin Research, Amsterdam, and Landsteiner Laboratory, Academic Medical Centre, University of Amsterdam, Department of Experimental Immunohematology

Department of Social Medicine, Academic Medical Center, Amsterdam, the Netherlands

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TGM Vrijkotte

TGM Vrijkotte

Department of Social Medicine, Academic Medical Center, Amsterdam, the Netherlands

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M de Haas

Corresponding Author

M de Haas

Sanquin Research, Amsterdam, and Landsteiner Laboratory, Academic Medical Centre, University of Amsterdam, Department of Experimental Immunohematology

Dr M de Haas, Sanquin Research, Amsterdam, and Landsteiner Laboratory, Academic Medical Centre, University of Amsterdam, Plesmanlaan 125, 1066 CX Amsterdam, the Netherlands. Email [email protected]Search for more papers by this author
CE van der Schoot

CE van der Schoot

Sanquin Research, Amsterdam, and Landsteiner Laboratory, Academic Medical Centre, University of Amsterdam, Department of Experimental Immunohematology

Department of Social Medicine, Academic Medical Center, Amsterdam, the Netherlands

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GJ Bonsel

GJ Bonsel

Department of Social Medicine, Academic Medical Center, Amsterdam, the Netherlands

Institute Health Policy and Management, Erasmus Medical Centre, Rotterdam, the Netherlands

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First published: 11 March 2009
Citations: 58

Source of the study: OPZI (detection and prevention of pregnancy immunisation) project: the nationwide evaluation of pregnancy screening for RBC antibodies other than anti-D, and of antenatal anti-D prophylaxis in the Netherlands, performed by Sanquin Research and the Academic Medical Centre of the University of Amsterdam, financed by the Council of Health Insurances.

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.

Population Cases: consecutive pregnancies (n = 900) with non-RhD immunisation identified from 1 September 2002 to 1 June 2003 and 1 October 2003 to 1 July 2004; controls (n= 968): matched for obstetric caregiver and gestational age.

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; 95% CI: 11.4–24.6), 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-nonD-antibodies 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. Pregnancy-related 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.