immune system in pregnancy: friend or foe?

ABSTRACT

Pregnancy is an intriguing immunological paradox; how does an allogeneic fetus survive despite a potentially antagonistic maternal immune system, while tissue allografts succumb to rapid immunological rejection? While several hypothetical models have been proposed in the last five decades to explain the immunological success of pregnancy, the model that has survived the test of experimentation is the one that proposes a state of immunomodulation during pregnancy. Several factors appear to prevent the rejection of the fetus. Yet, pregnancy can be compromised by a variety of complications such as recurrent spontaneous miscarriage, preeclampsia and preterm delivery. Research in the field of immunology of pregnancy has opened up the possibility of cellular immune effectors that might underlie these pregnancy complications. Particularly interesting are the effects that pro-inflammatory andanti-inflammatory cytokines have on the conceptus and thus on the success and failure of pregnancy. This review focuses on the association between some cytokines and successful pregnancy on the one hand, and between other cytokines and complications of pregnancy as also the possible pathways of effector function of cytokines in pregnancy loss. This review proceeds to discuss the therapeutic redirection of cytokine profilestowards one that is favorable to the success of pregnancy