The principal findings of this study were as follows: 1) Among 35 pregnant women with SLE, 16 women (45.7%) developed APO; 2) Proteomic analysis of mid-trimester amniotic fluid showed different profiling pattern between the SLE patients without APO (Group 1) and the SLE patients with APO (Group 2); 3) The expression of FLNA, SVEP1, LCAT, and TGM2 was significantly increased in the SLE patients with APO (Group 2) compared with the SLE patients without APO (Group 1). Here, FLNA is linked to systemic lupus erythematosus.