He also analysed data on social disadvantage at the time of birth and at the time of the cognitive assessment.
Dr Schneider found, in line with previous studies, that the adolescents with greater gestational age tended to have better cognitive abilities.
However, he also found that preterm babies aren't as far behind their full-term peers as researchers once thought.
"The postnatal environment seems to be playing an important role in whether or not a preterm child is able to overcome that initial risk of reduced brain development," he said.
"Reduced connectivity in the brain, associated with microstructural abnormalities from preterm birth, is likely contributing to the cognitive deficits in these children.
"But these abnormalities seem to be amenable to improvement depending on the environment the child grows up in, particularly as an infant, and might account for why some preterm children do better than others."
He said further research needs to be done to determine how different factors in the home environment drive specific aspects of brain development.
Early nutrition and enrichment through physical and intellectual stimulation are likely to have key roles, he said.
Every year, 10 per cent of Australian babies are born preterm.
The research was published in the The Journal of Paediatrics.
- AAP