[Variants of pathological immaturity of the placenta and their role in fetal development]

Morphologic evaluation of 125 placentas in various pregnancy and neonatal disturbances versus 46 normal placentas of different gestation provided the basis for recognition of 4 basic variants of the villous tree immaturity. Variant I is marked by embryonal villi close in structure to the villi of normal placentas (8-12 weeks gestation). Variant II presents intermediate immature and mature branches demonstrating the morphology of mean-caliber placental villi (13-28 weeks gestation). Variant III involves irregular sclerosed villi (23-24 weeks gestation). These variants are concerned with pathologic placental immaturity. There is also another variant which is confirmed by the evidence gained and can be related to a borderline condition between health and pathology--dissociated placentation. A favourable neonatal prognosis depends on a large amount of terminal special villi and compensatory placental angiomatosis.