OBJECTIVE: This study was undertaken to determine the risk of rare complications during pregnancy for women with systemic lupus erythematosus. STUDY DESIGN: By using the Nationwide Inpatient Sample from 2000-2003, we compared maternal and pregnancy complications for all pregnancy-related admissions for women with and without systemic lupus erythematosus. RESULTS: Of more than 16.7 million admissions for childbirth over the 4 years, 13,555 were to women with systemic lupus erythematosus. Maternal mortality was 20-fold higher among women with systemic lupus erythematosus. The risks for thrombosis, infection, thrombocytopenia, and transfusion were each 3- to 7-fold higher for women with systemic lupus erythematosus. Lupus patients also had a higher risk for cesarean sections (odds ratio: 1.7), preterm labor (odds ratio: 2.4), and preeclampsia (odds ratio: 3.0) than other women. Women with systemic lupus erythematosus were more likely to have other medical conditions, including diabetes, hypertension, and thrombophilia, that are associated with adverse pregnancy outcomes. CONCLUSION: Women with systemic lupus erythematosus are at increased risk for serious medical and pregnancy complications during pregnancy.