Immunology of early pregnancy.

The results of immunization of women with recurrent spontaneous abortion with paternal lymphocytes are described. The women we have treated were those with more than two spontaneous abortions with the same partner, who did not have evidence of genetic or other causes of recurrent abortion. Only women with recurrent abortion and no more than one live child were considered suitable for treatment. The success of treatment before pregnancy was 77%, similar to that found in our original double-blind controlled trial of immunization. The failures of treatment were found to cluster in those women who did not make detectable cytotoxic antibody after treatment, and who did not become pregnant within 90 days. Those women who did develop antipaternal antibody after immunization showed a protective response with no significant drop in efficiency in the year after immunization. A further group of women are described who were treated in the early part of pregnancy. The success rate was very high when the treatment was given within 40 days of the last period, and was less effective the later in pregnancy it was given. Birthweight, gestational age and malformation rate of the babies born after treatment were not different from those found in the normal population.