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Romanian Journal of Morphology and... 2022Next to A and B antigens, agglutinogen D exhibits the highest immunogenicity. Following the transfusion of D-positive red blood cells (RBCs), almost 80% of D-negative... (Review)
Review
Next to A and B antigens, agglutinogen D exhibits the highest immunogenicity. Following the transfusion of D-positive red blood cells (RBCs), almost 80% of D-negative recipients develop anti-D antibodies (Abs). Subsequently, anti-D immunization further promotes the synthesis of Abs towards other blood group antigens in or outside the Rh system. The D antigen is also involved in 95% of cases of hemolytic disease of the newborn. Transfusions, hemotherapy, grafts, and obstetric history (abortions, ectopic pregnancy, births) are all risk factors for Rh isoimmunization. In the case of ABO compatibility between mother and fetus, Rh-positive fetal RBCs that have reached the maternal bloodstream are not destroyed by group agglutinins, and Rh antigenic sites are not hidden by the maternal immune system. But a Rh-negative mother with a homozygous Rh-positive husband will certainly have a Rh-positive fetus. As it has an irreversible evolution, the Rh isoimmunization once installed cannot be influenced in the sense of decreasing the Ab titer, therefore, injectable globulin has no effect. A particular case was that of a newborn with Rh system incompatibility associated with hereditary spherocytosis The clinical balance at birth reflects the severe jaundice of the female newborn of 3140 g, gestational age 38∕39 weeks, extracted by lower-segment transverse Caesarean section, with a double loop nuchal cord, Apgar score 8. Because the jaundice was severe and atypical (face and upper chest), we considered the possibility of coexistence of hemolytic disease of the newborn by Rh blood group incompatibility associated with hereditary spherocytosis, as it turned out to be true and mentioned. Changes in genes encoding proteins in the structure of the RBC membrane have amplified hemolysis induced by maternal-fetal isoimmunization in the Rh system. Massive hemolysis accentuated by congenital spherocytosis, confirmed later, imposed blood transfusion and dynamic monitoring.
Topics: Blood Group Incompatibility; Cesarean Section; Female; Hemolysis; Humans; Infant; Infant, Newborn; Jaundice; Pregnancy; Pregnancy Complications; Rh Isoimmunization
PubMed: 36074689
DOI: 10.47162/RJME.63.1.26 -
JAMA Sep 2023While population-level data suggest Rh immunoglobulin is unnecessary before 12 weeks' gestation, clinical evidence is limited. Thus, guidelines vary, creating confusion... (Observational Study)
Observational Study
IMPORTANCE
While population-level data suggest Rh immunoglobulin is unnecessary before 12 weeks' gestation, clinical evidence is limited. Thus, guidelines vary, creating confusion surrounding risks and benefits of Rh testing and treatment. As abortion care in traditional clinical settings becomes harder to access, many people are choosing to self-manage and need to know if ancillary blood type testing is necessary.
OBJECTIVE
To determine how frequently maternal exposure to fetal red blood cells (fRBCs) exceeds the most conservative published threshold for Rh sensitization in induced first-trimester abortion.
DESIGN, SETTING, AND PARTICIPANTS
Multicenter, observational, prospective cohort study using high-throughput flow cytometry to detect circulating fRBCs in paired maternal blood samples before and after induced first-trimester abortion (medication or procedural). Individuals undergoing induced first-trimester abortion before 12 weeks 0 days' gestation were included. Paired blood samples were available from 506 participants who underwent either medical (n = 319 [63.0%]) or procedural (n = 187 [37.0%]) abortion.
EXPOSURE
Induced first-trimester abortion.
MAIN OUTCOMES AND MEASURES
The primary outcome was the proportion of participants with fRBC counts above the sensitization threshold (125 fRBCs/5 million total RBCs) after induced first-trimester abortion.
RESULTS
Among the 506 participants, the mean (SD) age was 27.4 (5.5) years, 313 (61.9%) were Black, and 123 (24.3%) were White. Three of the 506 participants had elevated fRBC counts at baseline; 1 of these patients had an elevated fRBC count following the abortion (0.2% [95% CI, 0%-0.93%]). No other participants had elevated fRBC counts above the sensitization threshold after induced first-trimester abortion. The median change from baseline was 0 fRBCs, with upper 95th and 99th percentiles of 24 and 35.6 fRBCs, respectively. Although there was a strong association between the preabortion and postabortion fRBC counts, no other baseline characteristic was significantly associated with postabortion fRBC count.
CONCLUSIONS AND RELEVANCE
Induced first-trimester abortion is not a risk factor for Rh sensitization, indicating that Rh testing and treatment are unnecessary before 12 weeks' gestation. This evidence may be used to inform international guidelines for Rh immunoglobulin administration following first-trimester induced abortion.
Topics: Adult; Female; Humans; Pregnancy; Abortion, Induced; Immunoglobulins; Prospective Studies; Rh Isoimmunization; Risk; Pregnancy Trimester, First; Erythrocytes; Young Adult; Black or African American; White
PubMed: 37750879
DOI: 10.1001/jama.2023.16953 -
PloS One 2020In the mid-20th century, Hemolytic Disease of the Fetus and Newborn, caused by maternal alloimmunization to the Rh(D) blood group antigen expressed by fetal red blood...
In the mid-20th century, Hemolytic Disease of the Fetus and Newborn, caused by maternal alloimmunization to the Rh(D) blood group antigen expressed by fetal red blood cells (i.e., "Rh disease"), was a major cause of fetal and neonatal morbidity and mortality. However, with the regulatory approval, in 1968, of IgG anti-Rh(D) immunoprophylaxis to prevent maternal sensitization, the prospect of eradicating Rh disease was at hand. Indeed, the combination of antenatal and post-partum immunoprophylaxis is ~99% effective at preventing maternal sensitization to Rh(D). To investigate global compliance with this therapeutic intervention, we used an epidemiological approach to estimate the current annual number of pregnancies worldwide involving an Rh(D)-negative mother and an Rh(D)-positive fetus. The annual number of doses of anti-Rh(D) IgG required for successful immunoprophylaxis for these cases was then calculated and compared with an estimate of the annual number of doses of anti-Rh(D) produced and provided worldwide. Our results suggest that ~50% of the women around the world who require this type of immunoprophylaxis do not receive it, presumably due to a lack of awareness, availability, and/or affordability, thereby putting hundreds of thousands of fetuses and neonates at risk for Rh disease each year. The global failure to provide this generally acknowledged standard-of-care to prevent Rh disease, even 50 years after its availability, contributes to an enormous, continuing burden of fetal and neonatal disease and provides a critically important challenge to the international health care system.
Topics: Erythroblastosis, Fetal; Female; Humans; Immunotherapy; Infant, Newborn; Pregnancy; Rh Isoimmunization; Rh-Hr Blood-Group System; Rho(D) Immune Globulin
PubMed: 32687543
DOI: 10.1371/journal.pone.0235807 -
Canadian Medical Association Journal Aug 1972
Topics: Amniocentesis; Blood Group Incompatibility; Erythroblastosis, Fetal; Female; Fetal Death; Hospitalization; Humans; Iatrogenic Disease; Infant, Newborn; Infant, Premature; Isoantibodies; Maternal-Fetal Exchange; Obstetric Labor, Premature; Paternity; Pregnancy; Pregnancy, Multiple; Rh-Hr Blood-Group System; Triplets
PubMed: 4626766
DOI: No ID Found -
Indian Pediatrics Mar 2023
Topics: Humans; Rh Isoimmunization; Iron Overload
PubMed: 36916367
DOI: No ID Found -
The New England Journal of Medicine Jan 2000Invasive techniques such as amniocentesis and cordocentesis are used for diagnosis and treatment in fetuses at risk for anemia due to maternal red-cell alloimmunization.... (Clinical Trial)
Clinical Trial
Noninvasive diagnosis by Doppler ultrasonography of fetal anemia due to maternal red-cell alloimmunization. Collaborative Group for Doppler Assessment of the Blood Velocity in Anemic Fetuses.
BACKGROUND
Invasive techniques such as amniocentesis and cordocentesis are used for diagnosis and treatment in fetuses at risk for anemia due to maternal red-cell alloimmunization. The purpose of our study was to determine the value of noninvasive measurements of the velocity of blood flow in the fetal middle cerebral artery for the diagnosis of fetal anemia.
METHODS
We measured the hemoglobin concentration in blood obtained by cordocentesis and also the peak velocity of systolic blood flow in the middle cerebral artery in 111 fetuses at risk for anemia due to maternal red-cell alloimmunization. Peak systolic velocity was measured by Doppler velocimetry. To identify the fetuses with anemia, the hemoglobin values of those at risk were compared with the values in 265 normal fetuses.
RESULTS
Fetal hemoglobin concentrations increased with increasing gestational age in the 265 normal fetuses. Among the 111 fetuses at risk for anemia, 41 fetuses did not have anemia; 35 had mild anemia; 4 had moderate anemia; and 31, including 12 with hydrops, had severe anemia. The sensitivity of an increased peak velocity of systolic blood flow in the middle cerebral artery for the prediction of moderate or severe anemia was 100 percent either in the presence or in the absence of hydrops (95 percent confidence interval, 86 to 100 percent for the 23 fetuses without hydrops), with a false positive rate of 12 percent.
CONCLUSIONS
In fetuses without hydrops that are at risk because of maternal red-cell alloimmunization, moderate and severe anemia can be detected noninvasively by Doppler ultrasonography on the basis of an increase in the peak velocity of systolic blood flow in the middle cerebral artery.
Topics: Blood Flow Velocity; Blood Group Incompatibility; Cordocentesis; Erythroblastosis, Fetal; Erythrocytes; Female; Fetal Blood; Gestational Age; Hemoglobins; Humans; Infant, Newborn; Isoantibodies; Middle Cerebral Artery; Pregnancy; Pregnancy Complications, Hematologic; Prospective Studies; ROC Curve; Reference Values; Rh Isoimmunization; Sensitivity and Specificity; Ultrasonography, Doppler, Pulsed; Ultrasonography, Prenatal
PubMed: 10620643
DOI: 10.1056/NEJM200001063420102 -
Canadian Medical Association Journal Aug 1972
PubMed: 20311964
DOI: No ID Found -
Canadian Medical Association Journal Aug 1972
PubMed: 20311963
DOI: No ID Found