False positive pregnancy tests in systemic lupus erythematosus

False positive, 'atypical ring' pregnancy tests were identified in 14 patients with systemic lupus erythematosus. The abnormality was associated with heavy proteinuria in 8 patients, menopause or drug-induced amenorrhea in 4 patients, and actual pregnancy in one patient. Serum levels of human chorionic gonadotropin were normal in 13 patients and elevated in the single patient with a true pregnancy.