Introduction <p>Trophoblast cells undergo ferroptosis in pregnancy-related diseases. HMGB1 participates in pathological ferroptosis. However, whether lipopolysaccharide (LPS) -mediated HMGB1 expression induces the ferroptosis of trophoblast cells and further spontaneous abortion (SA) remains unknown.</p> Methods <p>HMGB1 and ACSL4 expression were measured in villous tissues from 20 women with SA and 20 women with elective abortion. Human HTR-8/SVneo cells were treated with LPS to establish an in vitro abortion model. The hallmarks of ferroptosis including MDA, GSH, Fe²⁺ and ROS were detected using indicated assay kits.</p> Results <p>The levels of HMGB1 and ACSL4 in villous tissues from SA women were significantly higher than those in the normal control group. HMGB1 interacts with and stabilizes ACSL4 to promote the ferroptosis of trophoblast cells. Conversely, HMGB1 and/or ACSL4 inhibition attenuated LPS-induced trophoblast cells ferroptosis.</p> Conclusions <p>An HMGB1/ACSL4 axis is engaged in LPS-induced ferroptosis of trophoblast cells, and may be targeted to design treatments preventing SA.</p>