Premature infants have a known higher risk for poor neurological development, often leading to developmental and educational issues. However, these babies, born before 37 weeks, make up a small number of any generation, and new research shows that the 40 percent of babies born any more than a week before a full 40-week term are also at higher risk for having special education needs during childhood.

By analyzing the 2005 Scottish school census of 407,503 children and national birth records, researchers found that risk for special education needs steadily decreased with gestation duration all the way to 40 and 41 weeks—even though babies born between 37 weeks and 41 weeks are considered "at term." For the survey, special education needs included learning disabilities (such as autism, attention deficit hyperactivity disorder, dyslexia and others) and physical disabilities that can impair learning. The findings were published online June 8 in PLoS Medicine.

"The tendency of most previous studies to treat gestation as a binary factor (preterm versus term) has masked a dose-effect across the whole range of gestation," noted the researchers, led by Daniel MacKay, of the University of Glasgow's Section of Public Health.

And the sheer number of children who were born before 40 weeks (but after 37 weeks) mean that they constitute a greater percentage of special education children. Whereas preterm births accounted for about 5 percent of deliveries, they made up 3.5 percent of children needing special education. After adjusting for other factors, such as maternal demographics and mode of delivery, early term infants (delivered between 37 weeks and 39 weeks), had a 5.3 percent higher risk (than full term babies) for needing special education later.

"Historically, preterm delivery has been the main focus of research and clinical efforts because of the high risk to the individual infant," the researchers noted. But, even though neuro-developmental differences in early term infants might be "too subtle to be observed" at an early age, "at a population level, they are a contributor to special educations needs."

MacKay and colleagues noted that even though the increased risk for special education needs with early term delivery is slight, the issue has significant public health implications. "Early term births account for an increasing proportion of deliveries, and many of these are elective deliveries," the authors noted, adding that in the U.S. early term deliveries has increased 8.9 percent in the past decade, "largely due to an increase in cesarean section upon request."

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