how are they used in  prenatal therapy ?
Anti-RhD antibodies are administered as part of a prenatal treatment regimen to prevent sensitization that may occur when a Rh-negative mother has a Rh-positive fetus.
Antibody
 Anti-RhD antibodies are administered as part of a prenatal treatment regimen to prevent sensitization that may occur when a Rh-negative mother has a Rh-positive fetus. 
what is the role of antibodies in the immune system An antibody is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses. what are their forms ? The membrane-bound form of an antibody may be called a "surface immunoglobulin" (sIg) or a "membrane immunoglobulin" (mIg). what are their structures ? The size of an antibody molecule is about 10 nm. They have sugar chains (glycans) added to conserved amino acid residues. how are they used in disease therapy ? The diseases are often treated by inducing a short term form of immunity called passive immunity.
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Antibody [SEP] Prenatal therapy
Rho(D) immune globulin antibodies are specific for human RhD antigen. Anti-RhD antibodies are administered as part of a prenatal treatment regimen to prevent sensitization that may occur when a Rh-negative mother has a Rh-positive fetus. Treatment of a mother with Anti-RhD antibodies prior to and immediately after trauma and delivery destroys Rh antigen in the mother's system from the fetus. It is important to note that this occurs before the antigen can stimulate maternal B cells to "remember" Rh antigen by generating memory B cells. Therefore, her humoral immune system will not make anti-Rh antibodies, and will not attack the Rh antigens of the current or subsequent babies.