This sensitisation is more likely to happen during birth, but occasionally occurs in late pregnancy. These antibodies can cause anaemia, and sometimes death, for a Rh-positive baby in a subsequent pregnancy. Giving the mother anti-D after the first birth is known to reduce this problem. This review assessed two trials with moderate to high risk of bias and found that giving anti-D during pregnancy may help as well, although more research is required to confirm these possible benefits and identify any possible harms. However women receiving anti-D may be less likely to register a positive Kleihauer test in pregnancy and at the birth of a Rh-positive infant low quality evidence. Fewer women who receive anti-D during pregnancy may have Rhesus D antibodies in a subsequent pregnancy, with benefits for the baby, however this needs to be tested in studies of robust design.
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Medical uses[ edit ] In a pregnancy where the mother is RhD negative and the father is RhD positive, the probability of the fetus having RhD positive blood is dependent on whether the father is homozygous for RhD i. If the father is homozygous, the fetus will necessarily be RhD positive, as the father will necessarily pass on a Rh D positive allele.
If a fetus is RhD positive and the mother is RhD negative, the mother is at risk of RhD alloimmunization, where the mother mounts an immune response develops antibodies to fetal red blood cells.
This usually has minimal effect on the first such pregnancy; but, in a second such pregnancy, pre-existing maternal antibodies to RhD antigens on fetal red blood cells often leads to erythroblastosis fetalis , a condition which can be fatal to the fetus. RhIG is recommended in the UK after antenatal pathological events that are likely to cause a feto—maternal hemorrhage. There is insufficient evidence that the use of Rho D immune globulin after a spontaneous miscarriage is needed and a Cochrane review recommends that local practices be followed.
With the widespread use of RhIG, Rh disease of the fetus and newborn has almost disappeared in the developed world. In rare cases this can cause a baby to have a weakly positive DAT direct antiglobulin test due to sensitization of fetal cells from mothers who have received multiple doses of RhIG. However, no treatment is necessary as the clinical course is benign.
After delivery, a cord blood sample from infants born to D-negative mothers should be tested for the D antigen. If the neonate is D-negative, no further RhIG is needed. However, if the infant is D-positive, the mother should have a postpartum blood sample screened for fetomaternal hemorrhage in order to determine the appropriate dosage of RhIG to be administered. The rosette test is a sensitive method to detect fetomaternal hemorrhage of 10 cc or more.
This qualitative not quantitative test will be positive if fetal D-positive cells are present in the maternal sample, indicating a significantly large fetomaternal hemorrhage has occurred. A rosette test may be falsely positive if the mother is positive for the weak D phenotype and falsely negative if the neonate is weak D. If the mother is positive for the weak D phenotype, the rosette test should not be used; instead, a quantitative test such as the Kleihauer-Betke test or flow cytometry should be utilized.
If a fetomaternal hemorrhage in excess of 30 cc has occurred, additional testing is mandatory in order to determine the appropriate dosage of RhIG to prevent alloimmunization. A positive rosette test should be followed by a quantitative test such as the Kleihauer-Betke test or an alternative approach such as flow cytometry. See article on Kleihauer-Betke test for details on how the volume of fetomaternal hemorrhage is calculated.
The dosage of RhIG is calculated from the volume of fetal hemorrhage in mL. Postpartum RhIG should be administered within 72 hours of delivery. If prophylaxis is delayed, the likelihood that alloimmunization will be prevented is decreased. Symptoms of ITP include abnormal bleeding and bruising due to the reduction in platelet count.
Anti-D must be administered via the intravenous route when used in clinical situations requiring an increase in platelet count.
The following females are not candidates for RhIG: D-negative females whose fetus is known to be D-negative D-negative females who have been previously alloimmunized to D they have already formed an anti-D alloantibody Any D-positive females Women who test positive for one of the weak D mutations by molecular testing should be considered RhD positive and not receive RhIG  Women who test positive for one of the partial D mutations by molecular testing should be treated as RhD negative and receive RhIG as clinically indicated  History[ edit ] The first Rho D immune globulin treatment "skymed" was introduced by Ortho Clinical Diagnostics , a subsidiary holding of Jskymed , and was first administered on May 29, to Marianne Cummins in Teaneck, NJ.
Effectiveness was demonstrated in a clinical trial in and in Rhophylac was approved in the United States. The most common way anti-D products are manufactured is by a form of the Cohn cold ethanol fractionation process developed in the s. Variations of the Cohn method developed in the s may not completely clear aggregates of immunoglobulins, which can cause problems for patients if administered intravenously, and is a primary reason why most anti-Ds are for intramuscular use only.
A non-Cohn manufacturing variation is ChromaPlus process approved by the U. Steps are taken in the plasma-donor screening process and the manufacturing process to eliminate bacterial and viral contamination, although a small, residual risk may remain for contamination with small viruses. There is also a theoretical possibility of transmission of the prion responsible for Creutzfeldt—Jakob disease , or of other, unknown infectious agents. The IM-only preparation should never be administered IV due to the risk of complement system activation.
Multiple IM doses should be given at different sites or at different times within the hour window. Or, multiple IV doses can be administered according to the instructions in the package insert.
Names[ edit ] Rho D immune globulin is also spelled Rh0 D immune globulin letter o and digit zero are both widely attested; more at Rh blood group system - Rh nomenclature. Rhophylac is manufactured by CSL Limited. KamRho-D I.
Anti-D (Rho) Immunoglobulin
Function[ edit ] The function of IgD has been a puzzle in immunology since its discovery in IgD is present in species from cartilaginous fish to human with the possible exception of birds. In B cells , the function of IgD is to signal the B cells to be activated. By being activated, B cells are ready to take part in the defense of the body as part of the immune system. During B cell differentiation, IgM is the exclusive isotype expressed by immature B cells. IgD starts to be expressed when the B cell exits the bone marrow to populate peripheral lymphoid tissues. This is consistent with the reduction in the number of peripheral B cells, reduced serum IgE level and defective primary IgG1 response in IgD knockout mice.
Intrauterine procedures eg, insertion of shunts, embryo reduction. Miscarriage or threatened miscarriage after 12 weeks of gestation. Delivery - normal, instrumental or caesarean section. A maternal blood group and antibody screen should be undertaken to determine or confirm the RhD group and check for the presence of immune anti-D in these cases. A test for FMH is not required. Anti-D Ig should be given to all women who have an ectopic pregnancy or termination of pregnancy, regardless of method of management.
Rho(D) immune globulin
Medical uses[ edit ] In a pregnancy where the mother is RhD negative and the father is RhD positive, the probability of the fetus having RhD positive blood is dependent on whether the father is homozygous for RhD i. If the father is homozygous, the fetus will necessarily be RhD positive, as the father will necessarily pass on a Rh D positive allele. If a fetus is RhD positive and the mother is RhD negative, the mother is at risk of RhD alloimmunization, where the mother mounts an immune response develops antibodies to fetal red blood cells. This usually has minimal effect on the first such pregnancy; but, in a second such pregnancy, pre-existing maternal antibodies to RhD antigens on fetal red blood cells often leads to erythroblastosis fetalis , a condition which can be fatal to the fetus.