Nature of fetal adaptation to the uterine environment: a problem of sensory deprivation

0 B S T E T R I c I A N s are concerned with fetal cardiovascular physiology whenever they listen to a fetal heart. The problem is to distinguish between “normal” and “distress” situations. With knowledge only of the physiology of the adult as a guide, it is little wonder that reliable criteria of fetal distress are not readily available. The purpose of this paper is to set forth the character of fetal cardiovascular control and to provide a basis for the interpretation of it. With this new concept in mind, the problems of intrauterine fetal life and of neonatal adjustments after birth come more clearly into view. With the fetus in utero, attention focuses on the effects of the loss of gravitational pull on the body. The more fundamental question involved is the basic physiology of antigravity mechanisms upon the body. From this \;iewpoint, the entire spectrum of the consequences of weightIessness on the organism may be seen. Then evidence affirming the broad concept of sensory deprivation in general upon the body, and of antigrakrity deprivation in particular, may be looked for. In their book, Kybunetics of N&u,-al Systems,’ D. and K. Stanley-Jones establish a case for the concept that physiologic systems which are in a state of dynamic equilibrium-as are all living things---arc under the control of built-in mechanisms