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.

Comparative variability and interval correlation in linear growth of Hong Kong and Sudanese infants.

Growth in length of children during the first 10 months of life in Hong Kong and Khartoum is compared in terms of levels of between-child variability and length and increment correlations. In Khartoum, all measures of variability are strikingly greater, and correlational patterns differ strikingly from those in Hong Kong. Growth in Hong Kong can be explained largely in terms of a mixture of genetic determination and short-term homeostatic cycles. Such a model does not fit the Khartoum data where there is evidence of at least one additional and different systematic force. This appears to arise from infants who are long at birth being handicapped in their subsequent increment by early weaning, but may also involve widespread catch-up growth from birth. © 1992 Wiley-Liss, Inc.

Skeletal maturation of Hong Kong Chinese children in the first five years of life.

This report describes the skeletal maturity during the first five years of life of 492 Chinese children in Hong Kong in a longitudinal study. Hand-wrist radiographs taken half-yearly were assessed by the Tanner-Whitehouse method and rated according to the TW1 20-bone self-weighting maturity score. Skeletal age was in advance of chronological age in both sexes, but significantly more so in females, especially between 18 months and three years. The relationship of the skeletal maturation of these children to various socioeconomic factors is discussed, including the effect of preferential child rearing in favour of males.

Ventilatory capacity if healthy Chinese children: relation to habitual activity.

Ventilatory capacity, including forced expiratory volume (FEV 1-0) and forced vital capacity (FVC), and selected anthropometric indices have been obtained for 36 boys and 19 girls aged 5-10 years from a working class district in Kowloon. The ventilatory capacity is related to stature and is 13 per cent larger for boys than girls. After allowing for stature and sex the residual variation is significantly reduced by also allowing for the children's habitual activity. The ventilatory capacity of the more active children, including those who have lived all their lives in squatter huts on the hillsides, is on average 8 per cent larger than for the inactive children including those who have lived all their lives in tenement flats with lifts. The groups are apparently similar with respect to income, dietary pattern, intelligence and disease incidence, so that findings provide independent support for the hypothesis that the level of habitual activity during childhood contributes to the ventilatory capacity. The absolute level of ventilatory capacity resembles that of Nepalese children and differs from that of some other groups.