Fetal consequences of chronic substrate deprivation.

The aim of this paper is to review the mechanisms by which animal and human fetuses survive prolonged periods of substrate deprivation in utero. Two reasons why such information is important for those who care for growth-restricted fetuses and neonates are as follows. (1) Understanding the physiology is central to designing appropriate tests for determining fetal well-being. For instance, most currently available techniques for monitoring fetal well-being are actually better designed to detect acute than chronic fetal hypoxaemia. (2) There is increasing interest in the medium- and long-term consequences of fetal growth restriction on cardiovascular, neurological and lung function. As an example, the reasons why chronic oxygen deprivation may influence cerebral structure and function are discussed.