ObjectiveTo study the factors associated with fetal loss in Chinese women with systemic lupus erythematosus (SLE) in a large cohort of SLE patients in the CSTAR (Chinese SLE Treatment and Research Group) registry. MethodsWe compared the clinical characteristics and auto-antibody profiles between SLE patients with fetal loss and SLE patients with normal pregnancies. The relationship between selected variables and fetal loss was examined by univariate analysis and binary logistic regression analysis. ResultsA total of 992 patients with 2026 pregnancies were recruited. Fifty women experienced fetal loss, including 49 spontaneous abortion, eight stillbirths and three neonatal deaths. The overall fetal loss rate was 3.0% (60/2026). Arthritis and serositis were observed significantly more frequently (P<0.05) in normal pregnancy women. The rate of thrombocytopenia was significantly increased in patients with fetal loss (30.0% vs. 16.1%, P=0.010), while there was no statistically significant difference in the frequency of nephropathy, central nervous system involvement between the normal pregnancy group and fetal loss group. Factors that associated with fetal loss included anti-phospholipid antibodies (aPL) (OR 2.299; 95% CI 1.058-4.993; P=0.035) and anti-Sjogren syndrome antigen A (SSA) antibody (OR 2.283; 95% CI 1.275-4.088; P=0.005), and thrombocytopenia (OR 2.241; 95% CI 1.192-4.213; P=0.012). However, arthritis (OR 0.544, 95% CI 0.307-0.965, P=0.037) was associated with favorable fetal outcome. ConclusionsBoth univariate analysis and binary logistic regression analysis suggest that thrombocytopenia, aPL antibodies and anti-SSA antibody are associated with fetal loss in Chinese SLE women, while arthritis may be a possible factor related to favorable pregnancy outcome.