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 varied 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 postnatal 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 socio-economic status of the population with regard to the incidence of growth faltering in early life. Data were analysed from two longitudinal population-based studies, one from Sweden and one from Hong Kong. Of the Swedish cohort, 3.8% had a birth length below -2 SD scores; in the Hong Kong population the corresponding value was 11.9% (Swedish reference values were used in both studies). The following conclusions were made. Size at birth is important for postnatal growth, and the difference in length at birth of 9-10 cm between the two extreme birth length subgroups remains, on average, until maturity. This seems to be true for the two study populations with different degrees of socio-economic development. However, the rate of catch-up growth is highly dependent 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.
Karlberg
J
J
Department of Paediatrics, Queen Mary Hospital, University of Hong Kong, Hong Kong.
Albertsson-Wikland
K
K
Baber
F M
FM
Low
L C
LC
Yeung
C Y
CY
D000293:Adolescent; D001827:Body Height; D002648:Child; D002675:Child, Preschool; D006128:Growth / Q000502:physiology*; D006723:Hong Kong; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age / Q000502:physiology*; D008137:Longitudinal Studies; D013548:Sweden