PROPOSAL OF A NEW PLACENTAL FUNCTION INDEX - VASCULAR SCORE BY MACROSCOPIC OBSERVATION

Attempts have been made to clarify placental function in a variety of ways, but since most approaches were not morphologic they were of little use. Consequently, the concept of vascular score" has been developed on the basis of the macroscopic findings in the term placenta. It has been observed that the diameter ratio of subchorionic fetal arteries to veins varies as the distance between maternal and fetal circulations changes. This has a most important bearing on various metabolic changes between mother and fetus. This morphologic approach has been found to correlate well with clinical placental adequacy. The mechanism causing such morphologic changes in fetal vessels involves the development of capillaries in the terminal villi. The following two factors are considered to play a significant role: (a) Existence of immature tissues in mature placentas and (b) fibrination in villous stroma which hinders vascular development. © 1968."