Plasmapheresis for the treatment of repeated early pregnancy wastage associated with anti-P.

It has been proposed that the blood group antibody, anti-P, produced by p or Pk individuals may cause abortion early in pregnancy. The authors have studied and successfully treated a Pk woman with anti-P who had 13 consecutive first-trimester miscarriages. Anti-P was implicated as the cause of repeated pregnancy loss after extensive clinical, endocrinologic, immunologic, and chromosomal evaluations. To remove P blood group antibodies, plasmapheresis was begun at five weeks' gestation during the 14th pregnancy with one plasma volume exchange two to three times per week. This therapy resulted in a reduction in the titer of anti-P, and the patient was delivered of a viable female infant after 33 weeks' gestation. The management and outcome indicate that habitual abortion presumably due to anti-P can be successfully treated with plasmapheresis. This case provides additional evidence that anti-P is responsible for abortions in p or Pk women, and that these abortions are immunologically mediated.