Postnatal Growth and Development in Small-for-Date Babies

Until recently, all newborns with a birth weight lower than 2500 grams were defined as premature regardless of the gestational age, as proposed by the First World Health Assembly in 1948. The effect of this classification was that all newborns with a low birth weight were grouped together, so that infants with a low birth weight due to short gestation were compared with infants having a low birth weight due to intra-uterine growth retardation. Several authors pointed out the differences between these two kinds of infants: divergence in external appearance resulting from foetal malnutrition during the last weeks of gestation, in organ weight, as pointed out by Gruen wald (1, 2, 3, 4) or in oxygen consumption per kilogram body weight. Both groups have their own specific problems in postnatal life, which can influence the results of follow-up studies.