One of every nine infants in the United States is born early and, thus, with increased risk of cognitive difficulties, problems with motor skills, and attention deficit-hyperactivity disorder (ADHD), autism spectrum disorders and anxiety.
To get a better picture of how premature birth affects the brain, researchers used functional magnetic resonance imaging and diffusion tensor brain imaging to compare 58 babies born at full term with 76 infants born at least 10 weeks early. Each full-term baby was scanned on his or her second or third day of life. Each premature baby, meanwhile, received a brain scan within a few days of his or her due date.
The researchers found that some key brain networks -- those involved in attention, communication and emotion -- were weaker in premature infants, offering an explanation for why children born prematurely may have an elevated risk of psychiatric disorders.
White matter tracts in the brain are made of axons that connect brain regions to form networks. The researchers also found differences in preemies' resting-state brain networks, particularly in a pair of networks previously implicated in learning and developmental problems.
Among these resting-state networks is the default mode network, which tends to be most active when people are least active. The greatest differences between full-term and preterm babies were seen in this network and in the frontoparietal network. Both encompass brain circuits associated with emotion and previously have been linked to ADHD and autism spectrum disorders.
To see whether that's true, researchers are continuing to follow the babies, having completed follow-up evaluations when the children reached age 2, and again on some at age 5. The researchers plan another series of brain scans in a few years as the original study participants reach the ages of 9 or 10.