Figure 3.

Schematic representation of the cytokine profile from implantation to parturition. The line in black represents a normal pregnancy, while the line in grey represents one complicated with preeclampsia. During implantation, high amounts of pro-inflammatory cytokines such as IL-6, IL-15, and TNF-α are needed so that trophoblasts can invade the maternal vascular and endometrial tissue, which results in the recruiting and activation of immune cells. Then, pregnancy continues with a peaceful immune profile, allowing the fetus to grow. Finally, for parturition to occur, reactivation of inflammation must take place. In preeclampsia, an overall pro-inflammatory systemic environment with increased Th1 cytokines has been observed in maternal serum, amniotic fluid, and umbilical serum.