SummaryTwo hundred and eighty-nine pregnancies with rhesus antibodies delivered at Queen Charlotte's Maternity Hospital between 1974 and 1983 were reviewed. The cut-off antibody titre. measured by the indirect Coombs' test, at which amniocentesis is routinely performed should remain at 1 in 16.In rhesus negative women, measurement of rhesus antibody levels is the principal method by which further investigation and management are planned. At Queen Charlotte's Maternity Hospital, titres are measured by the indirect Coombs' test and an amniocentesis is performed if the antibody titre is equal to, or greater than, 16. A small number of amniocenteses are carried out at titres of 8. We have reviewed this practice.