The maternal-fetal interface shares similarities with tumor tissues in terms of the immune microenvironment. Normal pregnancy is maintained due to the immunosuppressed state, but pyroptosis induced by MITA can trigger the body's immune response and disrupt the immunosuppressed state of the maternal-fetal interface, leading to abortion. In this study, we explored the role of MITA and TRIM38 in regulating pyroptosis and maintaining the immune tolerance of the maternal-fetal interface during pregnancy. Our findings show that the interaction between MITA and TRIM38 plays a crucial role in maintaining the immunosuppressed state of the maternal-fetal interface. Specifically, we observed that TRIM38-mediated K48 ubiquitination of MITA was higher in M2 macrophages, leading to low expression levels of MITA and thus inhibiting pyroptosis. Conversely, in M1 macrophages, the ubiquitination of K48 was lower, resulting in higher expression levels of MITA and promoting pyroptosis. Our results also indicated that pyroptosis played an important role in hindering the transformation of M1 to M2 and maintaining the immunosuppressed state of the maternal-fetal interface. These discoveries help elucidate the mechanisms that support the preservation of the immune tolerance microenvironment at the maternal-fetal interface, playing a vital role in ensuring successful pregnancy.