Motor and cognitive outcomes in nondisabled low-birth-weight adolescents: early determinants

Abstract

Objectives: To describe motor and cognitive outcomes in nondisabled low-birth-weight (LBW) adolescents and to determine the relation of specific prenatal, perinatal, and neonatal risk factors to these outcomes.

Design: A prospective epidemiological study.

Setting: An adolescent follow-up of a regional LBW (<2000 g) cohort born in or admitted to 3 hospitals between September 1, 1984, and June 30, 1987 (n = 1105). Of 862 eligible survivors, 628 (72.9%) underwent assessment at a mean age of 16 years; of these, 33 had severe disability that precluded psychometric evaluation. The 474 nondisabled adolescents undergoing assessment at home had slightly less social risk at birth than did all other nondisabled eligible adolescents.

Participants: The 474 nondisabled LBW adolescents assessed at home. Main Exposures Basic birth characteristics (social risk, sex, fetal growth ratio, and gestational age), neonatal cranial ultrasound abnormalities, and other early medical complications.

Main outcome measures: Riley Motor Problems Inventory and Wechsler Abbreviated Scales of Intelligence.

Results: Nondisabled LBW adolescents had an excess of motor problems compared with the normative sample. The IQ scores, although within the normal range, were significantly lower than population norms. Independent predictors of total motor problems included male sex, white matter injury on neonatal ultrasound, and days of ventilation. Independent predictors of lower Full Scale IQ scores included social disadvantage, fetal growth ratio, and white matter injury on neonatal ultrasound.

Conclusions: Specific prenatal, perinatal, and neonatal risk factors influence motor and cognitive performance in nondisabled LBW survivors well into adolescence, even when controlling for social risk. Advances in maternal-fetal and neonatal care can substantially improve these long-term outcomes.