PROBLEM: The role of antibodies against fetal or maternal antigens in maintaining or losing pregnancy is not clear. METHOD OF STUDY: Term-pregnant mice were injected with monoclonal antibodies against only fetal or fetal and maternal major histocompatibility complex class I molecules. The development of pregnancy was then followed. RESULTS: Antibodies against maternal, but not fetal, major histocompatibility complex class I molecules induced abortion in mice. The abortion occurred 6-8 hr after the administration of autoreactive antibodies. The abortion could only be induced after the formation of placenta. Antibodies against tumor necrosis factor-alpha could not prevent or postpone the abortion. Extensive bleeding has been detected in the placenta of aborting mice 3 hr after the administration of the antibodies. CONCLUSIONS: This study indicates that autoreactive antibodies present risk for pregnancy and that the damage leading to abortion induced by such antibodies most likely occurs at the maternal side of placenta.
PROBLEM: The role of antibodies against fetal or maternal antigens in maintaining or losing pregnancy is not clear. METHOD OF STUDY: Term-pregnant mice were injected with monoclonal antibodies against only fetal or fetal and maternal major histocompatibility complex class I molecules. The development of pregnancy was then followed. RESULTS: Antibodies against maternal, but not fetal, major histocompatibility complex class I molecules induced abortion in mice. The abortion occurred 6-8 hr after the administration of autoreactive antibodies. The abortion could only be induced after the formation of placenta. Antibodies against tumor necrosis factor-alpha could not prevent or postpone the abortion. Extensive bleeding has been detected in the placenta of aborting mice 3 hr after the administration of the antibodies. CONCLUSIONS: This study indicates that autoreactive antibodies present risk for pregnancy and that the damage leading to abortion induced by such antibodies most likely occurs at the maternal side of placenta.