Development of a group of infants after neonatal intensive care

Abstract

The aim of the investigation was to obtain a detailed evaluation of the development over the first 10 months after birth of very low birthweight infants (under 1750g), following admission to a neonatal intensive care unit. One hundred and three infants who met the research criteria were enrolled in the study. Full assessment was carried out for 94 subjects at 4 points in time (0-14 days, Term. 4 months and 10 months). Measures employed included cognitive, motor and neurological evaluation, and records were taken of prenatal, perinatal and family history, physical growth, parental attitudes towards aspects of child-rearing and development, infant temperament and behaviour, and general health after discharge from hospital. Comparisons were made between various groups of infants including males and females, under 1500g and equal to or above 1500g birthweight, under 32 weeks and equal to or above 32 weeks gestational age. There were few significant differences between the sexes for study variables. At 4 months and 10 months, the smaller infants and the less mature infants demonstrated poorer cognitive and motor functioning, and results indicated a clear trend towards improved scores for increasing birthweight and gestational age. At 10 months, the study population as a whole demonstrated delay in many areas of development, including vocalisation, memory processing, goal-directed behaviour, manipulative-motor ability, gestural and gross motor skills. The best perinatal and neonatal predictors of performance on the Bayley Scales at 10 months were gestational age, maternal amnionitis, infant infection, apnoea, duration of oxygen therapy, and administration of ampicillin to infants. Evidence from this study suggests that at 4 months and 10 months, any adjustment of Bayley scores to allow for the length of time the infant was born preterm, should be made with caution due to the possibility of overestimating levels of ability and concealing developmental problems which may be ameliorated with early intervention measures. One finding concerned the large amount of parent-infant contact during the child's hospitalisation and the predominance in the early weeks of positive maternal attitudes towards aspects of infant development. These features enhanced opportunities for the establishment of favourable interaction patterns. An examination of health factors confirmed reports in the literature of the susceptibility of the VLBW infant to illness within the first year of life. Whereas at 4 months, mothers' ratings of infant temperament revealed that infants under 1500g (and under 32 weeks' gestation) at birth, showed more negative characteristics than their larger (and more mature) peers, at 10 months this was no longer the case. At this age, however, compared with the latter infants, children of lower birthweight and gestational age were found to demonstrate a greater number of adverse features of behaviour as rated by the examiner. Theoretical assumptions were set out for the use of education and health professionals regarding the evaluation of VLBW infants at different stages of development, the question of the adjustment of test scores for the gestational age of the infant, and the influences of perinatal and neonatal management practices on mental and motor development. Further, a number of principles were formulated for the guidance of parents caring for these high risk infants.