Neonatal death in babies with rhesus isoimmunization.

In the 27 years, 1951--1977, 4315 babies weighing over 1 kg were born alive in Newcastle suffering from haemolytic disease of the newborn due to Rhesus isoimmunization; 197 (4.5 per cent) died within four weeks of delivery. Many babies with severe anaemia (cord Hb less than or equal to 8 g/dl) died of cerebral and/or pulmonary haemorrhage as a result of coagulation failure; others with hydrops had a chance of recovery with intensive care as long as there was no associated pulmonary hypoplasia. Hyaline membrane disease was no more common in babies with haemolytic disease than in other preterm babies of comparable birthweight, but incorrect assessment of gestational age prior to the induction of labour increased the risk of death from hyaline membrane disease. The introduction of closed chest cardiac massage virtually eliminated the risk of sudden unexpected death during exchange transfusion but there was still a 1.5 per cent chance of sudden circulatory collapse during exchange transfusion. Affected babies of less than 36 weeks gestation with respiratory problems face a substantial risk of kernicterus when the indirect serum bilirubin level exceeds 270 mumol/l (15 mg/100 ml). The establishment of a single referral centre for Rhesus isoimmunization reduced neonatal mortality in the area to half the national average in the early 1950's and this superiority was maintained throughout the next decade.