In addition to the upregulation of C3, identified by its association with the over-represented IGF signaling pathway, we observed upregulation of other complement related genes, C1R and CFH. The complement system has a key role in pregnancy, especially during the development of the maternal-fetal interface where the establishment of maternal immunotolerance allows for a semi-allogeneic existence between fetus and mother yet also protect the mother and fetus from infection[31]. This evidence concerns the gene C3 and infection.