Cytokine networks in the establishment and maintenance of pregnancy.

Pregnancy is an immunological compromise geared towards inducing maternal immunopermissiveness that promotes tolerance of the foetal allograft. This process is mediated by an extensive array of cytokines, which operate in a highly coordinated and complex network system at both local (compartmentalized) and systemic levels. These glycoproteins also play an active role in gametogenesis and act as embryotrophins in the maternal tract. In addition to being involved in the seminal plasma-induced priming of the uterus for the establishment of pregnancy, they mediate the embryo-maternal paracrine dialogue and thus orchestrate various facets of embryo implantation and trophoblast invasion. Cytokines are recognized regulators of embryogenesis and foetal development, and participate in the inflammatory triggering of the onset of labour in late pregnancy. Given their central role in gestation, deregulations in cytokine networks are correspondingly associated with a host of human pregnancy complications, including miscarriage, pre-eclampsia and preterm labour.