Anti-D immunoglobulin is a component of donated blood, harvested from people who have developed antibodies against 'positive blood'. The use of 'anti-D' has greatly reduced the incidence of Rhesus haemolytic disease for babies by reducing the chances of a woman forming antibodies from about 10%to 20% to about 0.2 to 1.5%.
The concept of giving a donated blood product to prevent the formation of antibodies was first discovered in 1900. It took another 66 years for scientists to develop anti-D immunoglobulin (or 'anti-D') and to show the benefits it could confer to pregnant women with a negative blood group having babies with a positive blood group. After extensive research trials conducted in the late 1960's anti-D immunoglobulin became widely available to all pregnant women with a negative blood group in the early 1970's.
Up until the last decade or so, 'anti-D' was readily available because many women who had been 'alloimmunised or sensitised' in their pregnancies, prior to the development of anti-D, donated their blood to produce the immunoglobulin injections needed for other women.
In the last 10 to 15 years, stocks of anti-D immunoglobulin have become very low worldwide. In the past in Australia, it has even become unavailable. This is because the incidence of women becoming sensitised is now quite rare. The routine use of the immunoglobulin (over the last 30 years or so) to women with a negative blood group after the birth of their babies and in some cases during their pregnancy, has outstripped the ever-decreasing number of blood donors with antibodies.
In an attempt to keep up stocks and to meet demand, some men with negative blood groups have volunteered to be been given small amounts of 'positive blood' to set up the antibody reaction in their own blood. After doing this, it has made it possible for the blood bank to produce anti-D immunoglobulin injections from the blood these men donate at regular intervals (usually every 3 months or so).