How clinically important are non‐D Rh antibodies?

Abstract

Introduction The advent of RhD immunoglobulin prophylaxis to prevent maternal RhD alloimmunization has reduced the incidence of this condition and its associated poor outcomes. Consequently, non‐D Rh antibodies now account for a greater proportion of alloimmunized pregnancies. These antibodies have been the subject of comparatively little research. This study investigated the incidence and clinical outcome of pregnancies affected by non‐D Rh alloimmunization at an Australian tertiary maternity service. Material and methods This was a retrospective study of all pregnancies with non‐D Rh antibodies (namely anti‐C, ‐E, ‐c, ‐e, ‐Cw as well as the compound antibodies anti‐CD, ‐cE and ‐ce) managed at the Royal Women's Hospital, Victoria, Australia, from 2009 to 2013 inclusive. Information collected included maternal demographics, details of the antibodies, course of the pregnancy and neonatal outcomes. Results During the study period, 115 non‐D Rh alloimmunized pregnancies were identified in 102 mothers. Forty‐nine pregnancies reached the critical titer (> 16) from non‐D Rh alone and 11 fetuses received intrauterine red blood cell transfusion. Labor was induced or cesarean section performed in 38 cases. Forty‐three neonates were admitted to the special care nursery and 59 received phototherapy. Nine received treatment for anemia and 10 neonates received intravenous immunoglobulin. Conclusions Non‐D Rh alloimmunization is a relatively uncommon complication of pregnancy, occurring in only .33% of pregnancies in the study period. It can lead to significant fetal/neonatal morbidity (and may lead to mortality). The most severe outcomes (including perinatal deaths) were mostly associated with the compound antibodies anti‐CD and anti‐cE, or a non‐D Rh antibody in conjunction with anti‐D.

Hyporegenerative anemia in anti‐M‐associated hemolytic disease of the fetus

“…With the introduction of anti‐D immunoglobin prophylaxis, the incidence of RhD alloimmunization in RhD‐negative women has become dramatically reduced, and its associated poor perinatal outcome has decreased remarkably 1 . Maternal RhD alloimmunization has been reduced from 16% to 0.3% after routine RhD immunoglobin treatment during pregnancy in high‐income countries 2 . Therefore, non‐RhD alloimmunization has gradually attracted our attention.…”

Distribution of maternal red cell antibodies and the risk of severe alloimmune haemolytic disease of the foetus in a Chinese population: a cohort study on prenatal management

“…Haemolytic disease of the foetus and newborn (HDFN) is the most common aetiology of haemolytic anaemia in foetuses and hyperbilirubinaemia in neonates[ 1 ]. As the widespread prophylactic use of anti-D immunoglobulin has greatly decreased the incidence of Rh(D) alloimmunization from 16 to 0.3% in Western countries[ 2 , 3 ], the incidence of HDFN caused by non-Rh(D) antibodies has increased to 2.8‰~3.3‰[ 4 – 6 ]. However, the incidence of anti-D-related HDFN still contributes to the morbidity and mortality of foetuses and newborns in China[ 7 ].…”

Questioning universal use of O– red blood cells in intrauterine transfusions

“…It is pertinent to note, however, that although the c antigen is widely prevalent in the US population, the incidence of anti-c alloimmunization is not common. In a study by Healsmith et al, 18 0.33% of pregnancies in the study period (2009–2013) were complicated by non-Rhesus D antibody alloimmunization; of 115 deliveries, only 15 (13%) were complicated by anti-c alloimmunization. On the other hand, anti-c is consistently in the top 5 most common IgG antibodies found in pregnant women and in the top 3 most common causes of severe HDFN.…”