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Babies born prematurely are three times more likely than other children to develop autism, ADHD and emotional disorders. now researchers think they may understand why. They found evidence that preemies are born with weak connections in some critical brain networks. NPR's Jon Hamilton sent this report from the Society of Neuroscience meeting in Chicago.
JON HAMILTON, BYLINE: Researchers from Washington University in St. Louis suspected that the brains of premature infants were different from birth, so the team used two forms of MRI to compare the brains of 58 full-term babies with those of 76 babies born at least 10 weeks early. Cynthia Rogers, a child psychiatrist, told reporters the full-term babies were scanned as soon after they were born while the premature babies were scanned at their expected due date.
CYNTHIA ROGERS: And what we found was that preterm infants indeed have abnormal structural brain connections.
HAMILTON: Rogers says the team focused on the bundles of nerve fibers, or tracts, that connect areas of the brain thought to be involved in ADHD, autism and emotional disorders.
ROGERS: We were really interested that the tracts that we know connect areas that are involved in attention and emotional networks were heavily affected in preterm children.
HAMILTON: Weak connections make it harder for these brain areas to work together to focus on a goal or read social cues or regulate emotions. Rogers says the team plans to continue monitoring the brains of the children in the study to see which ones actually develop disorders. Another team attending the neuroscience meeting wanted to know whether the brain differences in preemies are present in the womb. Moriah Thomason from Wayne State University in Detroit said new MRI technology gave the team a way to safely answer the question.
MORIAH THOMASON: And the way that we do this is we invite women that are pregnant to come in for an MRI, and the MRI is focused on the brain of the developing fetus.
HAMILTON: The teams scanned the fetuses of 36 women during the 30th week of pregnancy. Half the women went on to deliver prematurely and half had full-term babies. Thomason says the team focused on fibers that connect the two halves of the brain, and the results were clear.
THOMASON: Term fetuses had higher levels of connectivity than the preterm-born. So this really fits nicely with what we've seen in neonates and infants, really saying that already, these systems, prior to birth, are showing some of these differences.
HAMILTON: So what this most recent study is suggesting is that it's not premature birth itself causing the brain problems, but the problems may come from the same factors - like stress or illness - that contribute to a baby being born prematurely. Jay Giedd, a child psychiatrist from the University of California, San Diego, says the new research does a good job revealing the problem in premature brains. The trick, he says, will be to find a solution.
JAY GIEDD: The trouble is we don't really know how to change the connections very well. Can we can do it with videogames, exercise, meditation, yoga, diet? So a lot of ideas, but what actually tweaks these circuit formations for good or ill?
HAMILTON: And Giedd says ultimately, repair work on those faulty brain circuits should begin before a child is born. Jon Hamilton, NPR news, Chicago.