Foetal nutrition, foetal growth restriction and health later in life

Retarded intrauterine growth has been linked to increased risk of perinatal mortality and morbidity, sudden infant death and poorer health later in li fe. The independent variables used in these studies are mainly neonatal siz e parameters, such as weight, ponderal index and ratios of head and abdomin al measures. These are, in terms of foetal development and growth, crude pa rameters. This paper discusses the concepts of growth retardation used in m ost clinical and epidemiological studies. it is: again emphasized that smal l for gestational age (SGA) and intrauterine growth retardation (IUGR) are different concepts. SGA is a size parameter that may or may not reflect res tricted foetal growth and is therefore of limited value. Even IUGR, defined as retarded foetal growth rate, may be a too crude a criterion to select f oetuses with short- and long-term health risks. Other biophysical measureme nts, such as foetal blood flow patterns and biochemical parameters, may be helpful in a better selection of these foetuses and infants. Furthermore, d ifferent causes of IUGR, e.g. poor maternal nutrition versus insufficient p lacental function, may not have the same effects on the foetus. The discrep ancies in the results of studies on the relationship between IUGR or foetal malnutrition and short- and long-term health risks may be explained by the crudeness of the independent variables used. In the future, research on th e biology of the developing human foetus should be more focused in the stud ies of the relationship between the intrauterine environment and nutrition and risk of poor health later in life.