FETAL GROWTH AND PLACENTAL FUNCTION

Fetal growth is largely determined by the availability of nutrients to the fetus. The fetus is at the end of a supply line that ensures deli very of nutrients from the maternal/uterine circulation to the fetus v ia the placenta. However, this supply line can not be regarded as a li near relationship. Maternal undernutrition will not only reduce global nutrient availability but will also influence the maternal and fetal somatotrophic axis. Both endocrine systems react in a very similar way to limited substrate supply. The hormones of the fetal somatotrophic axis: and in particular insulin-like growth factor (IGF)-1, are import ant regulators of fetal growth. Placental function is pivotal to mater no-fetal nutrient and metabolite transfer. Placental function in turn, is heavily influenced by the maternal and fetal growth hormone (GH)-I GF-1 system. The placenta itself is also an active endocrine organ and it produces a large number of hormones including GH and IGF-1 as well their corresponding receptors. Thus the placenta can no longer be con sidered merely a passive conduit for fetal nutrition. Rather, it is ac tively involved in the integration of nutritional and endocrine signal s from the maternal and fetal somatotrophic axes. (C) 1998 Elsevier Sc ience Ireland Ltd. All rights reserved.