Why Children Born as Late-Preterm Infants Should Be on Our Radar

August 1, 2008

For years, babies born between 32 and 36 weeks'gestation have been thought to have developmentaland neurological outcomes similar to those offull-term infants. Although studies have shownthat these infants are at greater risk for short-termmorbidities, such as respiratory distress, hyperbilirubinemia,hypoglycemia, and feeding problems,1 little researchhad been done regarding school outcomes for moderatepreterm(32 to 33 weeks) and late-preterm (34 to 36weeks) infants. Now a study in The Journal of Pediatricsby Chyi and colleagues2 has shown that these infantsmay also be at greater risk for difficulties in school laterin life.

Why Children Born as Late-Preterm InfantsShould Be on Our Radar

In a new study, such children hadmore difficulties in school.

For years, babies born between 32 and 36 weeks'gestation have been thought to have developmentaland neurological outcomes similar to those offull-term infants. Although studies have shownthat these infants are at greater risk for short-termmorbidities, such as respiratory distress, hyperbilirubinemia,hypoglycemia, and feeding problems,1 little researchhad been done regarding school outcomes for moderatepreterm(32 to 33 weeks) and late-preterm (34 to 36weeks) infants. Now a study in The Journal of Pediatricsby Chyi and colleagues2 has shown that these infantsmay also be at greater risk for difficulties in school laterin life.

Using the kindergarten cohort data of the US Departmentof Education Early Childhood LongitudinalStudy, the authors identified children who had been bornmoderate-preterm or late-preterm; they excluded thosewho had a history of anoxia or respiratory distress atbirth. At kindergarten, first grade, third grade, and fifthgrade, the authors examined direct assessment testscores, teacher rating scales, and the need for IndividualizedEducation Programs (IEPs) and special educationin both the study children and a control group of childrenborn as full-term infants.

The Chyi study found that the children born as latepreterminfants scored lower on the direct child assessmenttests for reading in kindergarten and in first grade,with teacher ratings showing lower abilities in fifth gradeas well. The assessment tests did not find a difference inmath abilities between those born late-preterm and thoseborn at full term; however, teachers rated the childrenborn late-preterm as having lower math abilities in kindergartenand first grade.

The children born as moderate-preterm infants werefound to have lower math test scores than those born atfull term in all grades and to have lower scores on readingtests in all grades but third. In addition, those born asmoderate-preterm infants were rated by teachers as havinglower reading levels than the children born at fullterm in all grades, and lower math aptitude in all gradesexcept kindergarten.

In kindergarten and first grade, the children bornas late-preterm infants were more likely than those bornat full term to require IEPs and to need special education.Of the 3 groups of children, those born as moderate-preterminfants required the most services at all grade levels.

As Chyi and colleagues state-and as Jain3 discussesin an editorial published with the article-this study hassignificant limitations, including demographic discrepanciesbetween the groups, participant attrition, and limiteddata availability secondary to use of a preexisting dataset.More than 30% of the children in each group were lostto follow-up (although the authors feel that the childrenborn preterm who were lost to follow-up had lower testscores and more difficulties early on than did the childrenborn at full term who were lost). Also, only parental reportswere available to assess gestational age and medicalcomplications at birth: no medical records wereaccessible.

Despite these limitations, this study is an importantearly step in understanding the differences between thebrains of preterm and full-term infants. Rather than assumingthat infants born without complication between32 and 36 weeks' gestation will develop similarly to fullterminfants, we must be aware of potential struggles theymay face. Moderate-preterm and late-preterm infants maybe at risk for difficulties in school and should be on ourradar for careful observation and evaluation.

References:

  •  Engle WA, Tomashek KM, Wallman C; Committee on Fetus and Newborn, American Academy of Pediatrics. "Late-preterm" infants: a population at risk. Pediatrics. 2007;120:1390-1401.

  •  Chyi LJ, Lee HC, Hintz SR, et al. School outcomes of late preterm infants: special needs and challenges for infants born at 32 to 36 weeks gestation. J Pediatr. 2008;153:25-31.

  •   Jain L. School outcome in late preterm infants: a cause for concern. J Pediatr. 2008;153:5-6.