[Basic pathogenetic mechanisms of chronic placental insufficiency].

Six basic mechanisms facilitating development of chronic placental deficiency, hypotrophy and fetal death are distinguished: 1) insufficiency of invasion of the extra-villous cytotrophoblast into the placental bed resulting in incomplete gestational restructuring of spiral arteries and reduction of uteroplacental circulation; 2) rheological disturbances in the intervillous space due to ultrastructural pathology of the glycocalyx and microvilli of the cytiotrophoblast; 3) pathological immaturity of microvilli and retraction of the diffusion surface; 4) disturbances of the villi perfusion resulting from prevailing development of the connective tissue components, reduction of stroma capillary bed and obliteration angiopathy at the level of supporting villi and umbilical cord; 5) placental barrier pathology; 6) endocrine deficiency resulting from the deficiency in the synthesis of human chronic gonadotropin during the first and, in part, second trimesters and the shortage of placental lactogen at the end of pregnancy.