Intraplacental coagulation in intrauterine growth restriction: cause or result?

Growth-restricted fetuses with complications of pregnancy exhibit significantly increased perinatal morbidity and mortality compared with normal growth fetuses. Coagulation-related lesions such as uteroplacental vessel thrombosis and perivillous coagulation in the placentas with intrauterine growth restriction (IUGR) are reported in complicated pregnancy, while fibrin depositions and intervillous thrombi are observed in half of the placentas of full-term uncomplicated pregnancy. These observations raise the question whether coagulation in the placental circulation is a cause for the development of IUGR. Recently published IUGR models in animals demonstrate that antiphospholipid antibodies and procoagulant platelet-derived phospholipids induce IUGR with histopathological changes of coagulation-related lesions in the placenta. These experiments suggest that enhanced coagulation in the placental circulation can induce IUGR and that hypercoagulable states remain one of the important factors in the development of IUGR.