Immunotherapy of habitual abortion.

Many cases of habitual abortion have been assumed to be due to hyporesponsiveness to the spouse's antigens encountered in pregnancy. Immunization by paternal leukocytes has been used to potentiate the immune response and prevent further miscarriages. This treatment has been highly controversial in terms of efficacy, mode of action, and side effects. More recently immunoglobulin has been used as passive immunization for similar indications. In our experience immunotherapy is effective; 80% of patients have subsequent live births. The most significant results are seen in patients with five or more abortions, in whom 66% of subsequent pregnancies develop normally compared to 20% in a control group. We have used antipaternal complement-dependent antibody (APCA) production after immunization as a marker of immune response. APCA correlates with beneficial outcome in the next pregnancy. APCA may also be associated with cytokines, which may enhance embryonic and trophoblast development. Immunoglobulin may similarly provide the relevant antibodies or cytokines. At present a large scale meta-analysis is being performed to confirm or refute the efficacy of this treatment. This meta-analysis may resolve the controversy.