The ability of the chemiluminescence test to predict clinical outcome and the necessity for amniocenteses in pregnancies at risk of haemolytic disease of the newborn

The chemiluminescence test measures the ability of anti-D to sensitise red cells for recognition by monocytes. It predicts clinical outcome in haemolytic disease of the newborn with greater precision than quantification of anti-D levels by AutoAnalyzer. However, whether or not the chemiluminescence test can, or should, affect clinical management is not clear. Of 56 alloimmunised women referred to a single fetal medicine unit, 30 underwent a total 63 amniocenteses to establish the extent of fetal haemolysis. Overall, chemiluminescence test results were a better predictor of amniocenteses with elevated bilirubin levels than the AutoAnalyzer (P < 0.01). Chemiluminescence results > 30% were always associated with elevated bilirubin levels. The chemiluminescence test might be used to prompt the direct evaluation of fetal haemolysis in patients with borderline levels of anti-D (5-15 IU/mL). However, the ability of the test to predict amniocenteses with normal bilirubin levels was less clear.