Abstract:
Perinatal associations of low birth weight and its long term sequelae were surveyed and the resulting hypotheses examined in a study of 240 children classified by birth weight, gestational age and sex. Subjects were placed in small for gestational age, pre-term appropriate for gestational age, control, pre-term small for gestational age, low birth weight with gastroenteritis and very low birth weight groups. Assessment was blind and, where necessary, groups were randomly selected. Data were gathered from four stages of the subjects’ development; the pregnancy, the newborn period, pre-school and school age. Analysis of pregnancy data showed that some aspects of the intrauterine environment provided by a number of mothers was less than optimal. In the neonatal period, the low birth weight groups were at some disadvantage and, further, there were aspects where there was some evidence that either the treatment or the condition for which it was required could possiblY influence subsequent development. The pre-school period was marked by sex differences, particularly in cognitive functioning. Disadvantage in all instances was confined to the low birth weight male groups. Some events in the prenatal, perinatal and neonatal periods appeared to be associated with poorer performance on intelligence tests more than four years later. Among these influences were mothers' smoking habits, temperature, duration of tube feeding and gastroenteritis while in hospital. Assessment at school revealed the same pattern of cognitive development among the subgroups that had been apparent at the pre-school stage. The pre-term males found adjustment to school difficult and made slow progress in reading in comparison with the females belonging to the same group. At this age the term - small for gestational age group was still lagging behind in physical development. It was concluded that the low birth weight males constituted a group who were ‘at risk’ because of slower cognitive development. This was particularly evident in so far as the pre-term males were concerned.