Pre-term babies at risk of neurocognitive delay

24 April 2013

Findings of a University of Canterbury research project show children born very pre-term are at high risk of cognitive delay and impairment.

Pre-term babies at risk of neurocognitive delay - Imported from Legacy News system

Findings of a University of Canterbury research project show children born very pre-term are at high risk of cognitive delay and impairment.

By the age of four, at least a third of very pre-term born children (compared to around 15 percent of full-term children) were subject to some form of cognitive delay.

"At age six, a similar pattern of results was observed. Although there was some suggestion that the proportion of very pre-term children subject to intellectual and function delay may have increased somewhat,’’ UC Professor Lianne Woodward says.

Importantly, the study found that white matter abnormalities seen on children’s MRI scans were a strong independent predictor of later cognitive problems. White matter is the cabling network of the brain which allows different parts of the brain to communicate with each other.

"Children born very pre-term who had no evidence of cerebral white matter abnormalities on their neonatal MRI scan were found to have similar levels of cognitive functioning to their full term born peers once social background and other factors were taken into account.

"In contrast, children born very pre-term with white matter abnormalities on neonatal MRI were at increased risk of cognitive impairment, with these risks increasing as the severity of white matter abnormalities increased.”

"We had previously shown that cerebral white matter abnormalities were an important predictor of cerebral palsy by age two, but results were less clear when it came to predicting cognitive functioning, in part due to the young age of study children,” Professor Woodward says.

The current findings, based on assessments at ages four and six, provide a valuable update to these earlier findings.

Professor Woodward carried out her research with Dr Samudragupta Bora at UC’s Canterbury Child Development Research Group. Professor Woodward is now based at Washington University in St Louis, but retains an adjunct faculty position at UC.

The study investigated one group of 104 very pre-term (32 weeks) infants and another group of 107 full-term (37-41 weeks) infants who were admitted to the Neonatal Intensive Care Unit at Christchurch Women’s Hospital over a two-year period.

Very pre-term birth is among the leading public health problems in Europe, the US and Australasia, placing immense burden on families, as well as health, education and social services.

"International estimates suggest the average lifetime costs associated with significant motor and cognitive disability are very high, with these costs not including the hidden costs borne by families.

"We believe these findings will be of wide interest to paediatricians, psychologists and neuroscientists. To date, most follow-up studies in very pre-term born children have tended to focus on the risks of severe impairment and disability.

"However, given the substantial numbers of very pre-term survivors with mild cognitive impairment, this group appears to be important.

"An increasing number of children will likely experience high-incidence, low severity conditions such as learning disabilities, ADHD and developmental coordination disorder that compromise classroom learning.

"Findings suggested that very pre-term infants who are spared cerebral white matter abnormalities can be expected to have similar levels of pre-school and early school age cognitive functioning as their full-term peers with respect to general intelligence, language, working memory, inhibitory control and cognitive flexibility,’’ Professor Woodward says.

For further information please contact:
Kip Brook
Media Consultant
Student Services and Communications
University of Canterbury
Ph: (03) 364 3325
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