This study was undertaken to determine the risk of rare complications during pregnancy for women with systemic lupus erythematosus.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.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.Women with systemic lupus erythematosus are at increased risk for serious medical and pregnancy complications during pregnancy.