RhDimmunoglobuline

RhDimmunoglobuline, commonly known as Rh(D) immune globulin, is a plasma-derived preparation containing antibodies against the RhD antigen. It is used to prevent the formation of anti-D antibodies in Rh-negative individuals who may be exposed to Rh-positive red blood cells, most notably in pregnancy and around childbirth. By blocking maternal sensitization to the D antigen, RhIg reduces the risk of hemolytic disease of the fetus and newborn in future pregnancies.

Mechanism and scope of use

RhD immune globulin works by binding to any RhD-positive red blood cells that enter the maternal bloodstream, enabling their clearance before the mother’s immune system can mount a detectable anti-D antibody response. It is primarily indicated for Rh-negative pregnant women with an Rh-positive fetus or unknown fetal Rh status, and for routine prophylaxis during pregnancy and after delivery if the newborn is Rh-positive. It is also used after events that may cause fetomaternal hemorrhage, such as miscarriage, abortion, amniocentesis, or abdominal trauma.

Administration and dosing

Dosing varies by country and clinical scenario. A common prophylactic strategy is administration at about 28 weeks of gestation and within 72 hours after delivery if the infant is Rh-positive. Additional doses may be given after events with potential fetomaternal bleeding, with the dose guided by the estimated volume of fetal red blood cells transferred (often assessed by laboratory tests such as the Kleihauer-Betke test).

Safety and considerations

RhD immune globulin is derived from human plasma and is processed to reduce infection risk. Rare allergic or anaphylactic reactions can occur. It should not be given if the mother is already alloimmunized to the D antigen. Ongoing developments include monoclonal anti-D products as alternatives in some settings.

See also: Rh incompatibility, hemolytic disease of the newborn.