Cognitive and motor differences among low birth weight infants: impact of intraventricular hemorrhage, medical risk, and social class.

The independent impacts of severe intraventricular hemorrhage, other common medical complications of prematurity, and socioeconomic status on the development in the second year of life of 32 low birth weight subjects were explored. Outcome measures included standard tests of mental and motor development, an evaluation of language competence, and an assessment of information processing ability in a habituation/recovery paradigm. Partial correlations indicated that intraventricular hemorrhage influences cognitive and motor development independently of the other predictor variables. Socioeconomic status predicted language ability and recovery of attention to a novel stimulus independent of the other predictors. Medical complications other than intraventricular hemorrhage also made an independent contribution to the variance in language outcome. Implications of these findings are discussed.