NUTRITION AND FETAL GROWTH

Nutrient supply to the fetus is a key factor in the regulation of feta l growth. However, the direct supply of nutrients to provide building blocks for tissue growth is likely to be only a minor component of thi s regulation. The indirect effects of nutrition on fetal endocrine and metabolic status, and on the interaction between the fetus, placenta and mother all of which must be coordinated to allow fetal growth are also important. Maternal undernutrition may alter the growth of the fe tus and its different component tissues in a way which cannot be expla ined solely on the basis of reduced substrate supply during the rapid growth phase of the tissues involved. Adaptation to altered substrate supply, during both undernutrition and refeeding, involves sequential changes in the metabolic and endocrine interactions between the fetus and the placenta. In addition, undernutrition has long-term consequenc es for the fetus. There is evidence for nutritional programming of fet al endocrine and cardiovascular systems before birth. Nutritional effe cts may also persist over more than one generation. The effects of nut rition on fetal growth are far more complex than simply those of subst rate deprivation.