BORN SMALL-FOR-GESTATIONAL-AGE - CONSEQUENCES FOR GROWTH

A large number of studies have documented a strong correlation between size at birth and subsequent height, although the reported incidence of catch-up growth and consequently the impact on final height has var ied with time and between countries. These variations may be real, but could also be related to a number of methodological problems. The aim of this study was to explore two important aspects related to postnat al growth after disturbed fetal growth: first, the definition of small for gestational age (SGA), including the selection of cut-off points in defining shortness; and, secondly, the importance of the general so cio-economic status of the population with regard to the incidence of growth faltering in early life. Data were analysed from two longitudin al population-based studies, one from Sweden and one from Hong Kong. O f the Swedish cohort, 3.8% had a birth length below -2 SD scores; in t he Hong Kong population the corresponding value was 11.9% (Swedish ref erence values were used in both studies). The following conclusions we re made. Size at birth is important for postnatal growth, and the diff erence in length at birth of 9-10 cm between the two extreme birth len gth subgroups remains, on average, until maturity. This seems to be tr ue for the two study populations with different degrees of socio-econo mic development. However, the rate of catch-up growth is highly depend ent on the definition of SGA, on the rate of catch-up growth in early life and on the incidence of growth faltering between 6 and 18 months of age.