Slightly early birth may still spell trouble later in school, study finds

Babies born moderately early—eight to four weeks premature—are more likely than their full-term peers to struggle in kindergarten and grade school, say researchers at Lucile Packard Children's Hospital and the School of Medicine.

The results, from a study of a national database of young children, fly in the face of conventional wisdom that holds these "late preterm infants" are unlikely to suffer long-term effects from their early births. The findings also highlight the importance of regular developmental screening for this group to identify problems early.

"These kids appear to require more support in school," said pediatric developmental specialist Trenna Sutcliffe, MD. "They are about twice as likely at all grade levels studied to require special education or individual education programs, and teachers often indicate that their skills in math and reading are below average."

More than 80 percent of the 500,000 preterm infants born annually in the United States are born within this window of 32 and 36 weeks gestation.

Sutcliffe is a developmental pediatrician at the Mary L. Johnson Developmental and Behavioral Unit at Packard Children's. Lisa Chyi, MD, neonatology fellow and the first author of the research, presented the findings May 6 at the annual meeting of the Pediatric Academic Societies in Toronto.

Despite the findings, parents shouldn't panic. Although late premature infants, or LPIs, scored significantly lower on standardized math and reading tests in kindergarten and first grade than children who were born full term, these differences were no longer detectable by fifth grade even though teachers still identified the LPIs as struggling. Although it's not clear why, it's possible that the discrepancy may be a testimony both to the children's hard work and timely school or medical interventions that allow them to increase their test scores.

"The majority of children who were late preterm infants do very well," said Chyi, who was turned on to the research after fielding inquiries from alert teachers. "Most of them are not going to have an issue with school. Our hope is that an awareness of this increased risk will encourage those parents and teachers who do notice a child struggling to intervene early," she said. Appropriate intervention could range from a specialized education program at school to something as simple as parents working more with their child at home, depending on the degree of problem and the age of the child, said Chyi.

The researchers used a national database called the Early Childhood Longitudinal Study-Kindergarten Cohort to evaluate nearly 1,000 LPIs from kindergarten to fifth grade for the study. They compared the LPI students' reading and math test scores, teacher evaluations and rates of special education enrollment to more than 13,000 children born full term.

"This late preterm group has received very little research attention in the past," said Sutcliffe, pointing out that most developmental research has instead focused on more severely premature infants. "Physically speaking they're usually not terribly bad off at birth, and they may even be discharged very quickly."

But recent studies have indicated that LPIs are slightly more likely than full-term infants to be jaundiced and to have low blood sugar—medical blips that pale in the face of the much more severe problems seen in very premature infants. The LPIs are also more likely to be re-hospitalized after discharge. Sutcliffe and others are now wondering if these subtle complications are responsible for the newfound school difficulties.

"Maybe these conditions carry long-term risk for brain development that we've not previously identified," said Sutcliffe. "Right now, small increases in bilirubin or decreases in blood sugar don't attract a lot of attention in this group of infants. Maybe we need to rethink how we manage these conditions."

Overall, though, it's important to keep the study findings in perspective, according to Sutcliffe. "We don't want to alarm parents," she said. "If you have a trusted pediatrician who follows the developmental screening guidelines of the American Academy of Pediatrics, it should be possible to identify and intervene early if potential problems arise."

For this study, Sutcliffe and Chyi's colleagues at Packard Children's and the School of Medicine include neonatology fellow Henry Lee, MD, and neonatologist Jeffrey Gould, MD, the Robert L. Hess Professor in Pediatrics.