Hundreds of babies are born prematurely each year in New Zealand, some as early as 23 weeks gestation and many develop and grow into healthy children and adults.
But the latest results from an internationally-acclaimed study following 110 New Zealand babies from birth has found that abnormalities in the brains of some born very prematurely persist into late childhood, affecting their motor skills, IQ and social skills.
The study, funded by the Health Research Council and the Neurological Foundation, has been following the babies - born at 32 weeks gestation or earlier - since 1998.
The researchers - Professor Lianne Woodward and neonatologists Professor Terrie Inder and Professor Nicola Austin - MRI scanned the brains of the trial babies at birth at Christchurch Hospital.
Their highly-acclaimed early work discovered that abnormalities within the developing white matter or "cabling networks" of the brain after birth could potentially explain the motor and cognitive impairments often experienced by children born very prematurely.
"On MRI we could see subtle abnormalities in the brain's white matter that didn't show up on ultrasound," says Professor Woodward.
"We needed to find out if these abnormalities would potentially lead to further changes in the brain or if the brain was able to repair and recover."
In the latest phase of the study, taken from MRI scans of the same babies brains at age 12, the team found that white matter abnormalities continued to be present in the brain in late childhood in one-third of the trial babies and that as the severity of early cerebral white matter abnormalities increased, their IQ trajectory dropped.
Mild white matter abnormalities were associated with a 4-point drop in IQ, moderate to severe abnormalities an 18-point drop, on average.
However they also discovered that early intervention and family upbringing has a powerful influence on children’s development and that a supportive family environment can help buffer children from adverse outcomes following premature birth.
"What we know about the brain is the ability for other areas of the brain to take over and improve function over time, allowing the brain to repair and recover," says Professor Nicola Austin.
The team has now developed a preschool screening strategy to identify those children born very prematurely who will be likely to go on to develop significant learning problems during their first four years of schooling.