The course of intellectual development in preterm and fullterm children: An 8-year longitudinal study

A total of 55 preterm children born at low to moderate risk and a comparison group of 100 healthy fullterm children were studied until they reached 8 years of age. Perinatal biomedical data and environmental data were considered as potential contributors to developmental outcome. The Budapest Binet intelligence quotients (IQs) were used as outcome measures. The mean IQs for both groups fell within the normal range at each measurement point. However, the differential patterns of IQ development in the preterm and term group underscore the significance of the age variable. Instead of a gradually declining impact of prematurity, the age effect resulted in a complex pattern. The considerable intra-group variability within the preterm group and the correlates of outcome suggest that biological hazards related to birth may have subtle long-term influences. Variables tapping the quality of home environment, however, clearly outweighed the perinatal risk factors in their ability to predict long-term outcomes. The results suggest a transaction between the two spheres of contributing factors. Long-term follow-up studies with multiple measurement points are essential if we are to understand the developmental implications of premature birth.