Infants Born Prematurely Take Longer to Process Information
TUESDAY, Nov. 12, 2002 (HealthDayNews) -- Premature infants as a group take longer to process information than full-term infants, New York researchers have found.
While it's known that many babies born prematurely do experience academic difficulties as they age, this study found that some components of the difficulties may present themselves early, says Susan Rose of the Albert Einstein College of Medicine.
"We're not trying to stigmatize babies," Rose stresses of the findings. "We're trying to find the roots of later problems and target interventions."
In the study, published in the November issue of Developmental Psychology, preemies took 30 percent more time and 20 percent more trials to process faces of babies they were shown, compared to infants who were born full-term.
This translates to a difference of about 10 seconds at 5 months of age, Rose says, and although it sounds minute, "it's a significant difference."
The children were tested at 5 months, 7 months and 12 months, although the premature infants were at their corrected age. Corrected age is the age the preemies would be if they had been born full-term, so they averaged about 10 weeks older than the full-term infants in the study. At their corrected age, their development is more on par with their peers, Rose explains.
The premature infants all weighed less than 1,750 grams at birth, and almost 92 percent of them were considered to be very low birth weight, weighing less than 1,500 grams when born. The full-term babies all weighed more than 2,500 grams at birth.
There were 153 full-term infants who started the study, of which 144 returned at seven months, and 126 at the year mark. There were 50 preemies at five months, 59 at seven months, and 56 at 12 months; some of who returned from earlier visits.
The infants were shown series of pictures of paired babies, one face that remained the same across trials and one that changed. The trials continued until an infant showed a regular preference for the new faces.
"Babies have a predilection for detecting what's new in the environment," Rose explains.
Having trouble remembering a new face presents a real problem that could haunt the child for life, she notes. "If you have to study a face for 30 seconds to remember it, that limits you."
While the premature infants did poorly as a group, this was not true for every single baby born early, she stresses, nor does it necessarily last. "The majority goes on to do well. About 30 percent go on to have difficulties."
The researchers do not know what causes the preemies to have these problems, but speculate that respiratory distress syndrome (RDS), a problem noted in about 50 percent of premature infants, is implicated. "Those that had RDS were the worst off," Rose notes.
Dr. Saroj Saigal, a professor of pediatrics at McMaster University in Hamilton, Ontario, doesn't think RDS is the reason premature infants take longer to encode information.
Nowadays babies in distress at birth are ventilated, and "it's not a problem," she says. "We can perhaps attribute it to problems with the brain" such as lesions, she suggests, but there was no data on brain imaging, so she can only speculate.
Rose's study is interesting because it shows the problem exists early on, Saigal says: "It really is there at the start of infancy and not related to environmental factors."
"It's very solid research," adds John Hagen, executive officer of the Society for Research in Child Development. He points out that while the 5-month-old infants had a 10-second difference in encoding information compared to full-term children, this gap decreased by 12 months of age, when the difference was five seconds. "The kids show lags; they're not bottoming out."
Rose says that testing for the problem early may mean it can be corrected. "I'm excited. We may be able to help these children," she says.
What To Do
To learn more about premature infants, visit the American Association for Premature Infants. The March of Dimes has more on low birth weight babies.
