Eleven patients with 18 pregnancies occurring during the course of systemic lupus erythematosus (SLE) were reviewed. Ten had long-standing lupus glomerulonephritis and a single patient developed glomerulonephritis during pregnancy. Patients were divided into those without (Group A) and those with (Group B) clinical evidence of renal disease or active SLE at conception. In Group A there were 10 pregnancies in five patients; all pregnancies were uncomplicated, except for mild superimposed pre-eclampsia in two, and all resulted in term delivery. Eight pregnancies in six patients occurred in Group B; four pregnancies were complicated by severe (2) or mild (1) superimposed pre-eclampsia and the onset of glomerulonephritis (1), resulting in three premature deliveries and a spontaneous abortion. The remaining four pregnancies were uncomplicated but resulted in one term delivery, one elective abortion, and two spontaneous abortions. None of the patients developed either renal failure or a rapidly progressive course following pregnancy.