Objective: To determine the frequency, nature, and severity of executive dysfunction (EDF) at 8 years of age in extremely low birth weight (ELBW)/very preterm infants who were born in the 1990s, compared with normal birth weight (NBW) control subjects.
Methods: A geographically determined cohort study was conducted in Victoria, Australia. The ELBW/very preterm cohort comprised 298 consecutive survivors at 2 years of age who had gestational ages <28 completed weeks or birth weights <1000 g and were born during 1991-1992. The NBW cohort comprised 262 randomly selected children of birth weight >2499 g matched on date of birth, gender, ethnicity, and health insurance status. The participation rate was 92% (275 of 298) for the ELBW/very preterm cohort and 85% (223 of 262) for the NBW cohort. Cognitive and behavioral measures of executive functioning were administered.
Results: The ELBW/very preterm cohort exhibited significant EDF compared with their NBW peers in all areas assessed. The cognitive assessment revealed global impairment rather than deficits in specific executive domains. The ELBW/very preterm children also displayed more behavioral problems indicative of EDF than the NBW children. Severe impairments were exhibited in only a small minority of ELBW/very preterm children. No statistical conclusions were altered after adjustment for sociodemographic variables or when children with substantial neurosensory impairment were excluded.
Conclusions: School-aged children who were born in the 1990s and were very preterm or had ELBW are at greater risk for developing EDF and require ongoing neuropsychological review throughout middle childhood.