How do preemies perform in school?

The large-scale study found that two-thirds of babies born at only 23 or 24 weeks were ready for kindergarten on time. Unexpectedly, nearly two percent of them even achieved gifted status in school. While these extremely premature babies often scored low on standardized tests, preterm infants born 25 weeks or later performed only slightly lower than full-term infants. In fact, as the length of pregnancy increased after 28 weeks, the differences in test scores were negligible.

The study will be published June 12 in JAMA Pediatrics.

"What excites me about this study is that it changes the focus for the clinician and families at the bedside from just focusing on the medical outcomes of the child to what the future educational outcomes might be for a child born early," said first author Dr. Craig Garfield, associate professor of pediatrics and of medical social sciences at Northwestern University Feinberg School of Medicine.

The longitudinal study analyzed more than 1.3 million babies born in Florida from 1992 to 2002 with gestational ages of 23 to 41 weeks who later entered Florida public schools between 1995 and 2012. The scientists matched the babies' vital statistic records with their Florida public school records to examine the association between being born early and educational performance.

"Many studies look at premature babies but very few of them look at their educational outcomes into middle school in such a large population," said Garfield, who also is an attending pediatrician at Ann & Robert H. Lurie Children's Hospital of Chicago. "What's special about this study is it speaks to the importance of administrative data sets and the ability to combine different data sets in ways that allow us to ask questions and get answers about how our children are doing in the long-run."

"While some people might be troubled that very premature infants tend to score well below their full-term peers on standardized tests, I believe that the glass is more than half-full," said senior author David Figlio, director of the Institute for Policy Research at Northwestern University. "Most infants born at 23 to 24 weeks still demonstrate a high degree of cognitive functioning at the start of kindergarten and throughout school."

While this study's data is strong, it does not account for some of these infants' medical issues related to preterm birth or provide information about why these children performed well in school, such as their biological make-up or if they received extra support from family or schools, Garfield said. Nevertheless, most babies born prematurely ended up performing reasonably well on standardized tests through middle school.

"Our future work in this area will focus on what parents and service providers can do to help future premature children to achieve their full potential," Garfield said.