Causes and clinical consequences of Rhesus (D) haemolytic disease of the newborn: a study of a Scottish population, 1985-1990.

Objective: To identify the reasons behind failures to prevent the development of Rhesus (D) haemolytic disease of the newborn.
Design: Retrospective analysis of the case records of all pregnancies that resulted in the birth of an infant with a positive direct antiglobulin test on the cord red cells born to Rh(D) negative women between 1 April 1985 and 31 March 1990.
Setting: Obstetric units in the South East Scotland region and the South East Scotland Regional Blood Transfusion Service Antenatal Laboratory.
Main Outcome Measures: The causes and clinical consequences of maternal immunisation to the Rhesus (D) antigen.
Results: Between 1985 and 1990, 80 pregnancies resulted in the birth of an infant sensitised with anti-D on the cord red cells. There were no deaths due to haemolytic disease, but considerable resources were deployed in obstetric and neonatal care for these pregnancies. Sufficient data were available to categorise the cause of maternal immunisation in 70 pregnancies. Seven cases were due to immunisation by pregnancy before 1970. Sixty-three cases could be attributed to failure of the Rhesus programme: 10 cases (16%) were due to failure to implement the programme adequately, the other 53 cases (84%) were due to failure of the current guidelines to provide adequate protection. Late immunisation in an uncomplicated pregnancy was the single commonest identifiable cause.
Conclusions: It is likely that substantial further reductions in Rhesus (D) immunisation and haemolytic disease of the newborn will require changes in the Rhesus prevention programme. In particular the role of antenatal prophylaxis requires detailed consideration.