Renal histology and pregnancy performance in systemic lupus erythematosus

Previous reports indicate that maternal and fetal outcome in pregnancies complicated by systemic lupus erythematosus (SLE) may be strongly influenced by the presence of renal disease. As the relationship between renal histology and clinical function in SLE is not consistent, prospective data on the outcomes of such pregnancies would aid patient counselling. Fifteen women with SLE had 18 pregnancies subsequent to renal biopsies, performed from 3 months to 8 years prior to conception. Their renal function was evaluated before, during and after pregnancy. Fourteen of 15 patients had evidence of renal involvement, based on by light and electron microscopic sections: 7 had mesangial involvement (WHO Class II); 5 had active focal or diffuse glomerulonephritis (Classes III and IV); two had membranous involvement (Class V); 1, no evident disease. Perinatal outcome was similar whether lesions were milder (8 continuing pregnancies, 4 term deliveries) or more severe (6 continuing pregnancies, 3 term deliveries). Clinical renal function was normal in all but 3 cases at the beginning of pregnancy; 2 additional patients experienced moderate deteriorations in renal function during pregnancy but recovered normal function in the puerperium. Fetal outcome was abnormal (3 premature deliveries, 1 neonatal death, 1 spontaneous abortion) in all cases where renal function was decreased, while 10 of 13 pregnancies in patients with normal renal function ended in term deliveries. The data suggest that currently preconceptual renal histology provides a less accurate basis for perinatal counselling than does the assessment of clinical renal function.