The adaptive structures of the fetal and placental arterial bed in chronic fetoplacental insufficiency

OBJECTIVE: To reveal the adaptive structures of arteries in the fetal organs and placenta in hypoxia of the latter, by establishing their structure, location, origin, and significance for blood circulation. SUBJECTS AND METHODS: Thirty-four antenatal deaths of fetuses at 28-29 weeks' gestation due to chronic fetoplacental insufficiency and 10 control cases were analyzed. The tissue pieces from different organs of the fetus and its placenta, which underwent histological, histochemical, and morphometric examinations, were explored. RESULTS: The organ blood bed of the fetus and its placenta in hypoplasia of the latter shows the increased development of adaptive arterial formations, the basis for which is smooth muscle fascicles. They have different origin and sites and vary in their structure, specific features of performance, and hemodynamic effects. CONCLUSION: The described formations contribute to the rational distribution of blood flows and in the organ beds and in the area of an undeveloped placenta, by providing the maximally possible reduction in the state of fetal trophic and oxygen deprivation.