Rh isoimmunization Archives - Revista Brasileira de Ginecologia e Obstetrícia
, , , Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2024;46:e-rbgo22
, , , RhD alloimmunization in pregnancy is still the main cause of hemolytic disease of the fetus and neonate (HDFN). Nevertheless, there are other antigens that may be associated with the occurrence of this phenomenon and that have been growing in proportion, given that current prevention strategies focus only on anti-RhD antibodies. Although not widespread, the screening and diagnostic management of the disease caused by these antibodies has recommendations in the literature. For this reason, the following review was carried out with the objective of listing the main red blood cell antigen groups described — such as Rh, ABO, Kell, MNS, Duffy, Kidd, among others — addressing the clinical importance of each one, prevalence in different countries, and recommended management when detecting such antibodies during pregnancy.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2024;46:e-rbgo22
, , , RhD alloimmunization in pregnancy is still the main cause of hemolytic disease of the fetus and neonate (HDFN). Nevertheless, there are other antigens that may be associated with the occurrence of this phenomenon and that have been growing in proportion, given that current prevention strategies focus only on anti-RhD antibodies. Although not widespread, the screening and diagnostic management of the disease caused by these antibodies has recommendations in the literature. For this reason, the following review was carried out with the objective of listing the main red blood cell antigen groups described — such as Rh, ABO, Kell, MNS, Duffy, Kidd, among others — addressing the clinical importance of each one, prevalence in different countries, and recommended management when detecting such antibodies during pregnancy.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2009;31(6):311-319
DOI 10.1590/S0100-72032009000600008
Alloimmunization is the formation of antibodies when there is an exposition of the individual to non-self antigens, as it occurs, for example, in the transfusion of incompatible blood and pregnancies, in whom the fetus express in its sanguineous cells antigens exclusively of paternal origin. This article is restricted to the alloimmunization against erythrocytes antigens in obstetric patients. Almost all the anti-erythrocytes antibodies can be fit in one of the 29 systems of already recognized sanguineous groups, being more implied in the hemolytic disease of the newborn anti-D, anti-c and anti-Kell, followed by anti-C, anti-E, anti e, anti-Fyª and anti-Jkª. The research of irregular antibodies, to permit the diagnosis of alloimmunizated people, and the modern genetic techniques have better characterized these patients for the prophylaxis and prenatal segment. The traditional accompaniment of the gestations of risk for hemolytic disease of the newborn, with the spectral analysis of the amniotic liquid and the intraperitoneal transfusion, has being quickly substituted for the Doppler ultrasound evaluation in the middle cerebral artery, the intravascular transfusion guided for ultrasonography in real time, beyond improvements in the materials and the quality of the blood, that in set, have raised the survival of the attempting fetus. Doubtlessly, the correct application of the prophylaxis with use of anti-D is successful with potential to reduce the alloimmunization cases.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2009;31(6):311-319
DOI 10.1590/S0100-72032009000600008
Alloimmunization is the formation of antibodies when there is an exposition of the individual to non-self antigens, as it occurs, for example, in the transfusion of incompatible blood and pregnancies, in whom the fetus express in its sanguineous cells antigens exclusively of paternal origin. This article is restricted to the alloimmunization against erythrocytes antigens in obstetric patients. Almost all the anti-erythrocytes antibodies can be fit in one of the 29 systems of already recognized sanguineous groups, being more implied in the hemolytic disease of the newborn anti-D, anti-c and anti-Kell, followed by anti-C, anti-E, anti e, anti-Fyª and anti-Jkª. The research of irregular antibodies, to permit the diagnosis of alloimmunizated people, and the modern genetic techniques have better characterized these patients for the prophylaxis and prenatal segment. The traditional accompaniment of the gestations of risk for hemolytic disease of the newborn, with the spectral analysis of the amniotic liquid and the intraperitoneal transfusion, has being quickly substituted for the Doppler ultrasound evaluation in the middle cerebral artery, the intravascular transfusion guided for ultrasonography in real time, beyond improvements in the materials and the quality of the blood, that in set, have raised the survival of the attempting fetus. Doubtlessly, the correct application of the prophylaxis with use of anti-D is successful with potential to reduce the alloimmunization cases.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2008;30(7):341-348
DOI 10.1590/S0100-72032008000700004
PURPOSE: to verify the correlation between ultrasonography heart measures and hemoglobin deficit in fetuses of alloimmunized pregnant women. METHODS: a transversal study, including 60 fetuses, with 21 to 35 weeks of gestational age, from 56 isoimmunized pregnant women. A number of 139 procedures were performed. Before cordocentesis for the collection of fetal blood, cardiac measures and femur length (FL) were assessed by ultrasonography. The external biventricular diameter (EBVD) was obtained by measuring the distance between the epicardic external parts at the end of the diastole, with the M-mode cursor perpendicular to the interventricular septum, in the atrioventricular valves. The measure of the atrioventricular diameter (AVD) was obtained by positioning the same cursor along the interventricular septum, evaluating the distance between the heart basis and apex. The FL was determined from the trochanter major to the distal metaphysis. The cardiac circumference (CC) was also calculated. To adjust the cardiac measure to the gestational age, each of these measures were divided by the FL measure. Hemoglobin concentration has been determined by spectrophotometry with the Hemocue® system. Hemoglobin deficit calculation was based in the Nicolaides's normality curve. RESULTS: direct and significant correlations were observed between the cardiac measures evaluated and the hemoglobin deficit. To predict moderate and severe anemia, the sensitivity and specificity found were 71.7 and 66.3% for EBVD and FL, 65.8 and 62.4% for AVD and FL, and 73.7 and 60.4% for CC and FL, respectively. CONCLUSIONS: ultrasonography cardiac measures assessed from fetuses of isoimmunized pregnant women correlate directly with hemoglobin deficit.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2008;30(7):341-348
DOI 10.1590/S0100-72032008000700004
PURPOSE: to verify the correlation between ultrasonography heart measures and hemoglobin deficit in fetuses of alloimmunized pregnant women. METHODS: a transversal study, including 60 fetuses, with 21 to 35 weeks of gestational age, from 56 isoimmunized pregnant women. A number of 139 procedures were performed. Before cordocentesis for the collection of fetal blood, cardiac measures and femur length (FL) were assessed by ultrasonography. The external biventricular diameter (EBVD) was obtained by measuring the distance between the epicardic external parts at the end of the diastole, with the M-mode cursor perpendicular to the interventricular septum, in the atrioventricular valves. The measure of the atrioventricular diameter (AVD) was obtained by positioning the same cursor along the interventricular septum, evaluating the distance between the heart basis and apex. The FL was determined from the trochanter major to the distal metaphysis. The cardiac circumference (CC) was also calculated. To adjust the cardiac measure to the gestational age, each of these measures were divided by the FL measure. Hemoglobin concentration has been determined by spectrophotometry with the Hemocue® system. Hemoglobin deficit calculation was based in the Nicolaides's normality curve. RESULTS: direct and significant correlations were observed between the cardiac measures evaluated and the hemoglobin deficit. To predict moderate and severe anemia, the sensitivity and specificity found were 71.7 and 66.3% for EBVD and FL, 65.8 and 62.4% for AVD and FL, and 73.7 and 60.4% for CC and FL, respectively. CONCLUSIONS: ultrasonography cardiac measures assessed from fetuses of isoimmunized pregnant women correlate directly with hemoglobin deficit.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2008;30(4):196-200
DOI 10.1590/S0100-72032008000400007
PURPOSE: to obtain an equation to estimate the volume of red blood cells concentrate to be infused to correct anemia in fetuses of pregnant women with Rh factor isoimmunization, based in parameters obtained along the cordocentesis previous to intrauterine transfusion. METHODS: a transversal study analyzing 89 intrauterine transfusions to correct anemia in 48 fetuses followed-up in the Centro de Medicina Fetal do Hospital das Clínicas da Universidade de Minas Gerais. The median gestational age at the cordocentesis was 29 weeks and the average number of procedures was 2.1. Fetal hemoglobin was assayed before and after cordocentesis, leading to the volume of transfused red blood cells concentrate. The determination of an equation to estimate the blood volume necessary to correct the fetal anemia was based in the blood volume necessary to raise the fetal hemoglobin in 1 g% (the difference between the final and the initial hemoglobin concentration divided by the transfused volume) and in the volume of the amount necessary to reach 14 g%, in the multiple regression analysis. RESULTS: the concentration of pre-transfusion hemoglobin varied between 2.3 and 15.7 g%. The prevalence of fetal anemia (Hb<10 g%) was 52%. The regression equation obtained in the determination of blood volume necessary to reach the concentration of 14 g% of Hb was: transfusion volume (mL)=18.2 - 13.4 x pre- intrauterine transfusion hemoglobin + 6.0 x gestational age in weeks. This equation was statistically significant (p<0.0001). CONCLUSIONS: the study has shown that it is possible to estimate the transfusion volume necessary to correct fetal anemia, based on easily obtainable parameters: gestational age and level of pre-transfusion hemoglobin.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2008;30(4):196-200
DOI 10.1590/S0100-72032008000400007
PURPOSE: to obtain an equation to estimate the volume of red blood cells concentrate to be infused to correct anemia in fetuses of pregnant women with Rh factor isoimmunization, based in parameters obtained along the cordocentesis previous to intrauterine transfusion. METHODS: a transversal study analyzing 89 intrauterine transfusions to correct anemia in 48 fetuses followed-up in the Centro de Medicina Fetal do Hospital das Clínicas da Universidade de Minas Gerais. The median gestational age at the cordocentesis was 29 weeks and the average number of procedures was 2.1. Fetal hemoglobin was assayed before and after cordocentesis, leading to the volume of transfused red blood cells concentrate. The determination of an equation to estimate the blood volume necessary to correct the fetal anemia was based in the blood volume necessary to raise the fetal hemoglobin in 1 g% (the difference between the final and the initial hemoglobin concentration divided by the transfused volume) and in the volume of the amount necessary to reach 14 g%, in the multiple regression analysis. RESULTS: the concentration of pre-transfusion hemoglobin varied between 2.3 and 15.7 g%. The prevalence of fetal anemia (Hb<10 g%) was 52%. The regression equation obtained in the determination of blood volume necessary to reach the concentration of 14 g% of Hb was: transfusion volume (mL)=18.2 - 13.4 x pre- intrauterine transfusion hemoglobin + 6.0 x gestational age in weeks. This equation was statistically significant (p<0.0001). CONCLUSIONS: the study has shown that it is possible to estimate the transfusion volume necessary to correct fetal anemia, based on easily obtainable parameters: gestational age and level of pre-transfusion hemoglobin.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2005;27(3):143-148
DOI 10.1590/S0100-72032005000300008
PURPOSE: to describe etiology, evolution and prevalence of hydrops fetalis in a cohort of pregnant women during a period of ten years (1992 to 2002) in a tertiary maternity. METHODS: a retrospective study was carried out in patients referred to the maternity of the Fernandes Figueira Institute, with diagnosis of hydrops fetalis, detected by ultrasonography, during the period from 1992 to 2002. The cases were selected according to etiology (immune or nonimmune) and evolution, performed invasive procedures and survival were compared between both groups. Analysis of variables was performed by Epi-Info 6.0 and a p value less than 0.05 was considered to be statistical significant. RESULTS: in ten years of follow-up, 80 patients with an initial diagnosis of hydrops were attended. The frequency of hydrops in this population was 1 in 157 live births. Rh immunization (immune group) was detected in 13 cases (16.2%), and for 67 cases (83.8%) nonimmune causes (nonimmune group) were considered. Major causes of nonimmune hydrops fetalis were idiopathic (40.2%), genetic (20.8%), infectious diseases (20.7%), and cardiopathy (7.4%). A difference was found in relation to maternal age in the immune group (mean = 32.8 years) when compared with the nonimmune group (mean = 28.7 years) (p=0.03), but gestational age at delivery was similar in both groups (mean = 33.6 weeks in the immune group and 33.1 weeks in the nonimmune group) (p=0.66). Amniocentesis and blood transfusion in utero were carried out more frequently in the immune group (p<0.001) and perinatal mortality was 53.8% in the immune group and 68.6% in the nonimmune group (p=0.47). Complementary research of IgG anti-parvovirus B19 antibodies was carried out in 41 of 67 cases of nonimmune hydrops, with 16 being positive for the presence of anti-B19 IgG antibodies. CONCLUSION: nonimmune etiology was the most common form of presentation of hydrops fetalis in our study. Perinatal mortality of this entity is still high and a substantial number of cases had no identified cause. Characterization of fetal karyotype and performance of specific parvovirus B19 serology could increase causal identification of nonimmune hydrops classified as idiopathic.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2005;27(3):143-148
DOI 10.1590/S0100-72032005000300008
PURPOSE: to describe etiology, evolution and prevalence of hydrops fetalis in a cohort of pregnant women during a period of ten years (1992 to 2002) in a tertiary maternity. METHODS: a retrospective study was carried out in patients referred to the maternity of the Fernandes Figueira Institute, with diagnosis of hydrops fetalis, detected by ultrasonography, during the period from 1992 to 2002. The cases were selected according to etiology (immune or nonimmune) and evolution, performed invasive procedures and survival were compared between both groups. Analysis of variables was performed by Epi-Info 6.0 and a p value less than 0.05 was considered to be statistical significant. RESULTS: in ten years of follow-up, 80 patients with an initial diagnosis of hydrops were attended. The frequency of hydrops in this population was 1 in 157 live births. Rh immunization (immune group) was detected in 13 cases (16.2%), and for 67 cases (83.8%) nonimmune causes (nonimmune group) were considered. Major causes of nonimmune hydrops fetalis were idiopathic (40.2%), genetic (20.8%), infectious diseases (20.7%), and cardiopathy (7.4%). A difference was found in relation to maternal age in the immune group (mean = 32.8 years) when compared with the nonimmune group (mean = 28.7 years) (p=0.03), but gestational age at delivery was similar in both groups (mean = 33.6 weeks in the immune group and 33.1 weeks in the nonimmune group) (p=0.66). Amniocentesis and blood transfusion in utero were carried out more frequently in the immune group (p<0.001) and perinatal mortality was 53.8% in the immune group and 68.6% in the nonimmune group (p=0.47). Complementary research of IgG anti-parvovirus B19 antibodies was carried out in 41 of 67 cases of nonimmune hydrops, with 16 being positive for the presence of anti-B19 IgG antibodies. CONCLUSION: nonimmune etiology was the most common form of presentation of hydrops fetalis in our study. Perinatal mortality of this entity is still high and a substantial number of cases had no identified cause. Characterization of fetal karyotype and performance of specific parvovirus B19 serology could increase causal identification of nonimmune hydrops classified as idiopathic.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2005;27(8):450-455
DOI 10.1590/S0100-72032005000800003
PURPOSE: to test a new, noninvasive method for the diagnosis of fetal anemia in red blood cell isoimmunized pregnancies. METHODS: the index obtained by the ratio between the ultrasonographic measurement of the biventricular outer dimension (BVOD) and femur length (both in centimeters) was correlated with fetal hemoglobin values in a cross-sectional study. Fifty-nine fetuses of isoimmunized pregnancies selected for invasive treatment and submitted to 130 cordocenteses for the diagnosis and treatment of anemia were included in the study. The cardiofemoral index was obtained immediately before the cordocentesis and the fetal hemoglobin index was obtained from fetal blood samples. Linear regression was carried out to assess the correlation between the index and fetal hemoglobin; ROC curve was applied to determine the most accurate cutoff for the diagnosis of the fetal hemoglobin concentration below 10g/dl. RESULTS: BVOD measurement varied from 1.6 to 4.7 cm (average 2.5±1.3cm), and length of the femur, from 3.0 to 6.9 cm (average 4.3±0.9 cm). The cardiofemoral index varied from 0.4 to 1.0 (average 0.6±0.1). A significant inverse correlation between the cardiofemoral index and fetal hemoglobin (R²=0.37 and p<0.0001) was observed. The cutoff of 0.60 was the best to predict a level of fetal hemoglobin below or equal to 10.0g/dl: 80.85% sensitivity, 83.13% specificity, 73.8% positive predictive value, and 88.46% negative predictive value, in the diagnosis of fetuses anemia. CONCLUSION: the cardiofemoral index allows for good accuracy in the prediction of fetal hemoglobin concentration below 10g/dl in red blood cell isoimmunized pregnancies. It may thus be applied as a noninvasive method to the diagnosis of this pathology.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2005;27(8):450-455
DOI 10.1590/S0100-72032005000800003
PURPOSE: to test a new, noninvasive method for the diagnosis of fetal anemia in red blood cell isoimmunized pregnancies. METHODS: the index obtained by the ratio between the ultrasonographic measurement of the biventricular outer dimension (BVOD) and femur length (both in centimeters) was correlated with fetal hemoglobin values in a cross-sectional study. Fifty-nine fetuses of isoimmunized pregnancies selected for invasive treatment and submitted to 130 cordocenteses for the diagnosis and treatment of anemia were included in the study. The cardiofemoral index was obtained immediately before the cordocentesis and the fetal hemoglobin index was obtained from fetal blood samples. Linear regression was carried out to assess the correlation between the index and fetal hemoglobin; ROC curve was applied to determine the most accurate cutoff for the diagnosis of the fetal hemoglobin concentration below 10g/dl. RESULTS: BVOD measurement varied from 1.6 to 4.7 cm (average 2.5±1.3cm), and length of the femur, from 3.0 to 6.9 cm (average 4.3±0.9 cm). The cardiofemoral index varied from 0.4 to 1.0 (average 0.6±0.1). A significant inverse correlation between the cardiofemoral index and fetal hemoglobin (R²=0.37 and p<0.0001) was observed. The cutoff of 0.60 was the best to predict a level of fetal hemoglobin below or equal to 10.0g/dl: 80.85% sensitivity, 83.13% specificity, 73.8% positive predictive value, and 88.46% negative predictive value, in the diagnosis of fetuses anemia. CONCLUSION: the cardiofemoral index allows for good accuracy in the prediction of fetal hemoglobin concentration below 10g/dl in red blood cell isoimmunized pregnancies. It may thus be applied as a noninvasive method to the diagnosis of this pathology.
