Prevention of rhesus (D) immunisation--some causes of failure in Northern Ireland.

DURING the past decade there has been a dramatic fall in the incidence and mortality from Rh haemolytic disease (Tovey 1976; Magee, lIarley, Campbell and McClure, 1969-78). This is due to two factors, firstly the appreciable fall in the number of Rh (D) negative women having babies, particularly if they had developed Rh antibodies previously; and secondly the routine administration of anti-D immunoglobulin to Rh (D) negative women delivered of Rh (D) positive infants. This prophylactic programme is aimed at prevention of Rh (D) immunisation, because once this occurs, there is a serious risk of haemolytic disease in any Rh (D) positive baby and this tends to become progressively more severe with increasing mortality in subsequent pregnancies (Walker, Murray and Russell, 1957). Recently it has become apparent that the decline in the incidence of Rh (D) immunisation has halted, and that a significant number of Rh (D) negative women still develop anti-D as a result of pregnancy. We present the results of an investigation into the causes of the problem in Northern Ireland and discuss the measures required to solve it.