Objective: Chorioamnionitis resulting from preterm labor leads to concurrent damage in both the placenta and fetal brain. This study aims to explore the impact of incorporating antioxidants and anti-inflammatory agents, specifically selenium (Sel) and dexpanthenol (Dex), into the standard magnesium (Mg) regimen, in mitigating this damage. Materials and Methods: A total of six pregnant rats were assigned to six distinct groups: control, lipopolysaccharide (LPS) (1 mg/kg, single intraperitoneal dose on day 17), Mg (60 mg/kg Mg, intraperitoneal), Mg+Sel (1 mg/kg, intraperitoneal), Mg+Dex (500 mg/kg, intraperitoneal), and Mg+Sel+Dex. On the 17th day of pregnancy, fetal brain and placenta tissues were harvested for histopathological examination and immunohistochemical evaluation of tumor necrosis factor-alpha (TNF-α) and neurofilament expression. Results: The histopathological assessment revealed LPS-induced hemorrhage and mild inflammatory cell infiltration in the placenta, and pronounced hyperemia along with minor hemorrhage in the fetal brain. The LPS group exhibited significantly elevated TNF-α expression in both placenta and fetal brain, coupled with reduced neurofilament expression in the fetal brain. In contrast, the groups treated with Mg alone and the combined Sel and Dex therapy exhibited moderate to substantial improvement in pathological findings across both tissues. The most notable enhancement was observed in the Mg+Sel+Dex group. Conclusion: Administration of Mg as a standalone treatment and the coadministration of Sel and Dex effectively shielded the placenta and fetal brain from LPS-triggered chorioamnionitis. However, the most prominent protective effect was observed in the Mg+Sel+Dex group.