Uterine, placental, renal biopsies, and fibrin deposits in toxemia of pregnancy.

Histopathologic lesions of toxemia of pregnancy found in 46 first trimester-induced abortions and 82 women with kidney biopsies are reviewed and discussed. Decidual arteriolar vasospasm and degeneration, syncytial trophoblastic degeneration, and chorionic villous fibrin deposits characterize the early toxemic changes of the uterus and placenta. Pure toxemic glomerular, arteriolar, tubular, and juxtaglomerular alterations were present in about 40% of the kidney biopsies. Others had arteriolar nephrosclerosis, chronic glomerulonephritis or both. Two women had renovascular hypertension. Excessive vascular permeability predisposed to fibrinogen leakage and fibrin deposits. The mechanisms of preclinical toxemia of pregnancy and clinical preeclampsia are considered in view of these biopsy observations.