TNF and rheumatoid arthritis: During pregnancy, TNF-α affects hormone synthesis, placental structure, and embryonic development,[37] and in vitro studies have shown that TNF-α on placental syncytial trophoblasts activates maternal monocytes bound to LFA-1 and induces apoptosis.[38] It has also been shown that TNF-α levels with preeclampsia are associated.[39] In addition, immune cells, cytokines, ROS, and gastrointestinal microorganisms are involved in the pathophysiological processes of RA.