• recurrent abortion;
  • immunotherapy;
  • blocking antibodies

ABSTRACT: Thirty-nine unexplained recurrent aborters underwent vaccination using husband's lymphocytes according to the previously reported protocol. No mixed lymphocyte culture reaction-blocking antibodies (MLR-BAbs) were observed in these patients prior to vaccination. Of 35 newly pregnant patients after vaccination(s), pregnancy successfully continued in 28 (80.0%) and have already been terminated with a liveborn offspring. Pregnancy outcome was also analyzed in unexplained recurrent aborters who revealed positive MLR-BAbs without immunotherapy. In this group, out of eight pregnancies in seven patients, five (62.5%) continued beyond their critical period of 14 wks of gestation. Three infants born from these pregnancies, however, presented severe abnormalities. Furthermore, outcome of 14 pregnancies in 12 unexplained recurrent aborters with negative MLR-BAbs was analyzed since they had become pregnant without immunotherapy; pregnancy was successfully continued in only four cases (28.6%). Thus, vaccination using husband's lymphocytes on unexplained recurrent aborters with negative MLR-BAbs is suggested to be effective. In addition, it is suggested that immunotherapy for patients with positive MLR-BAbs should be carefully followed.