The histopathology of placental insufficiency.

Voltaire, regarded by some as a realist and by others as a cynic, remarked that 'if God did not exist it would be necessary to invent him'. One suspects that this comment is equally applicable to placental insufficiency, a concept that has similarly attracted not only faithful adherence but also bewildered agnosticism or defiant disbelief. Placental insufficiency has been largely defined in clinical terms, principally by those who believe that the placenta is, during a normal pregnancy, extended to the full limit of its functional capacity. Adherence to this belief implies that any factor which adversely influences trophoblastic function, by no matter how limited an extent, will restrict the fetal supply of oxygen and nutrients, this resulting in fetal growth retardation, wasting, hypoxia or, in extreme cases, death. This clinical concept has been supported, to