TUESDAY, Nov. 23 (HealthDay News) -- Independent of maternal intelligence quotient (IQ), residential setting, and sociodemographics, children born late-preterm are at higher risk for having a lower IQ and more behavioral problems at age 6 than children from a full-term pregnancy, according to research published online Nov. 22 in Pediatrics.
Nicole M. Talge, Ph.D., of Michigan State University in East Lansing, and colleagues assembled data from a 1983 to 1985 study of low and normal birth weight infants in urban and suburban settings. In order to create 168 matched pairs, the researchers matched each singleton child born late-preterm (34 to 36 weeks' gestation) with a full-term counterpart whose birth weight was similar. Differences within pairs for IQ scores and teacher-reported behavioral problems were assessed at age 6, and the results were adjusted for maternal IQ, residential setting, and sociodemographic factors.
The researchers found that late-preterm birth was associated with an increased risk of full-scale and performance IQs below 85 (adjusted odds ratios [aORs], 2.35 and 2.04, respectively). Late-preterm birth was also associated with increased risk for high levels of internalizing problems, such as being anxious, depressed, or withdrawn, and attention problems (aORs, 2.35 and 1.76, respectively).
"Late-preterm birth is associated with behavioral problems and lower IQ at the age of 6, independent of maternal IQ, residential setting, and sociodemographics. Future research is needed to investigate whether these findings result from a reduction in gestational length, in-utero (e.g., obstetric complications) or ex-utero (e.g., neonatal complications) factors marked by late-preterm birth, or some combination of these factors," the authors write.