Prevention of rhesus immunization in Australia. The first seven years.

After seven years' general use of anti-Rh (D) immunoglobulin in Australia, it is clear that the rate of Rh immunization by pregnancy can be reduced to 1% or less by giving anti-D to women at risk soon after delivery. All Rh-negative women who have miscarriages or terminations of pregnancy should also be given anti-D. The Australian standard dose of 250 mug of anti-D is also much more than the minimum effective dose for most cases, and few more failures would occur if it were reduced to 100mug of antibody. Some of these may be prevented by screening maternal blood for the presence of fetal cells and giving further anti-D when large numbers are found. A trial has been conducted since 1970 to discover whether giving anti-D during pregnancy as well as at delivery will further reduce the rate of rhesus immunization. Results are still inconclusive. While giving anti-D during pregnancy appear to have no serious hazard for mother or infant, it will prevent few cases of rhesus immunization, and may not be justifiable. There has so far been little change in the incidence or mortality of haemolytic disease of the newborn in Australia that cen be attributed to the use of anti-D.