Lesions of toxemia of pregnancy, comprising decidual arteriolar thickening, narrowing, degeneration, and endothelial vacuolization with trophoblastic degeneration and fibrin thrombi attached to degenerated chorionic villi, were evident in 46 (14.1%) of 326 induced first trimester abortions. No clinical features of toxemia were present, and fetal development was not apparently affected.