Preeclampsia is characterized by increased vasoconstriction frequently associated with
increased platelet aggregation, reduced uteroplacental blood flow, and premature delivery.
Because prostacyclin antagonizes the vasoconstrictor, platelet-aggregating, and uterine-
activating actions of thromboxane, we considered the hypothesis that placental production of
thromboxane was increased coincident with decreased production of prostacyclin in
preeclampsia. Fresh human term placentas were obtained immediately after delivery from …