Comparison of data on births in women with systemic lupus erythematosus (SLE; n = 180) and in the general population in Norway (n = 498,849) has revealed links between disease activity and pregnancy outcomes. Patients with SLE had an increased risk of low birth weight in neonates (P < 0.001) and preterm birth (P = 0.003) compared with population controls, effects that were more pronounced in the setting of active disease. Patients with active disease also had an increased risk of pre-eclampsia compared with the general population or patients with inactive disease (P < 0.001 and P = 0.052, respectively).