TOXEMIA OF PREGNANCY may be the leading cause of maternal mortality and morbidity in the United States. It is an important cause of perinatal mortality and a statistically significant factor in children with later evidence of birth-associated damage.1 The etiology of toxemia is still unknown. Postmortem study of toxemia reveals lesions of the brain, lungs, liver, and kidney. Only the latter two lesions appear to be consistent and specific for toxemia. Liver lesions are usually associated with imminent fatality. In 1918 it was recognized that the renal glomerulus was the principle site of pathologic change.2 Further study disclosed a characteristic renal lesion in toxemia, confined to the glomerulus, in which all glomeruli were diffusely involved and in proportion to the severity of the disease.3 Additional data suggested that the glomerular lesion was the most sensitive pathological index of toxemia in the body.4 While all pathologists