Alloimmunization in a Rhesus (Rh) D-Negative Pregnant Woman With an Uncommon Rh Phenotype: A Case Report

TL;DR

This case report details a pregnant woman with a rare Rh blood type who developed antibodies, emphasizing the need for routine screening and proper Rh immunoglobulin use.

Contribution

The case highlights an uncommon Rh phenotype and the importance of genotype-informed transfusion planning in preventing Rh alloimmunization.

Findings

The patient had a rare dCe/dce (r′r) Rh phenotype and tested positive for anti-D antibodies.

No intrauterine transfusion was needed despite the risk of hemolytic disease of the fetus and newborn.

Routine antenatal screening and prophylactic measures are critical in preventing Rh alloimmunization.

Abstract

Rhesus (Rh) alloimmunization remains a critical concern in obstetrics, particularly in RhD-negative pregnant women who have not received postpartum Rh immunoglobulin (RhIg) prophylaxis. This report describes the case of a 19-year-old pregnant woman in her second pregnancy who had no documented administration of anti-D prophylaxis after her first childbirth. During routine screening at 28 weeks of gestation, her Indirect Coombs Test (ICT) showed strong positivity (3+), with an anti-D antibody titer of 1:128. Antibody identification confirmed anti-D specificity. Further immunohematological evaluation revealed that the patient had blood group B negative and an uncommon dCe/dce (also known as r′r) Rh phenotype, lacking D and E antigens. Though the fetus was at risk for hemolytic disease of the fetus and newborn (HDFN), there was no need for intrauterine transfusion during the pregnancy. This case highlights the importance of routine antenatal antibody screening, awareness of Rh phenotypes, and timely prophylactic measures to prevent Rh alloimmunization. Comprehensive monitoring and genotype-informed transfusion planning are especially crucial in resource-limited settings.

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