Anti-D(Rh₀) immunoglobulin

An anti-serum that contains antibodies against Rhesus (Rh) D factor (a substance present on the red blood cells of people with Rh-positive blood). Anti-D(Rh) immunoglobulin is given routinely at intervals during normal pregnancy and at delivery. An additional dose is also given after an amniocentesis, miscarriage, or any event in which the baby’s blood may enter the mother’s circulation. The injected antibodies prevent the woman from forming her own antibodies against Rh-positive blood, which might adversely affect a subsequent pregnancy. (See also haemolytic disease of the newborn; Rhesus incompatibility.)