During normal pregnancy a local hypercoagulable state is known to be essential for physiological placental haemostasis. However, small placental thrombi are frequently observed in women with pre-eclampsia (P-EC), and may compromise placental perfusion and fetal growth development, possibly leading to intrauterine death.
This suggests that, in addition to the thrombotic nature of placental vasculature, pre-disposing factors to thrombosis could cause or contribute to the development of P-EC. The etiology of P-EC is complex and the cause of coagulation activation in P-EC is not fully understood, but the release of pro-coagulant tissue factor (TF) into the maternal circulation may be implicated. Indeed, TF levels are high in the so-called obstetric tissues (placenta, decidua, myometrium, amniotic fluid). Studying the TF-dependent pathway of blood coagulation and its co-factors may help to elucidate some of the pathogenesis of P-EC and may provide a rational basis for its differential diagnosis and effective treatment.