Toxemic renal disease in incomplete molar pregnancy.

This communication describes the light, electron, and immunofluorescence microscopy of renal biopsy specimens from a patient with hydatidiform degeneration of the placenta and coexisting fetus. Symptoms of toxemia appeared in the 18th week of gestation and were accompanied by heavy proteinuria, decreased renal function, and disproportionately elevated serum uric acid concentration. The biopsy findings were consistent with the renal lesions of toxemia of pregnancy, although other renal diseases such as Henoch Schonlein nephritis or lupus proliferative glomerulonephritis cannot be excluded. Normal serological tests and disappearance of proteinuria, along with recovery of renal function to normal promptly after termination of pregnancy, tend to rule out other renal diseases. The molar transformation of the placenta, or the interaction with the kidney of certain humoral factors such as human chorionic gonadotropin which was markedly elevated in this patient, may be related to the pathophysiology of toxemia of pregnancy.