Research Tuesday: Impact of Prematurity on Language Skills at School-age

November 12, 2014
Kira Wright, CCC-SLP

November is an intense time for special educators in the public schools. Not only do we feel the time-sensitive pressures of Census, but instruction, assessment, progress measures, and paperwork are all in full swing, requiring a clear head and careful consideration. Demands on our time are numerous and being efficient is as prized as being thorough. 

At this time in the year, my most exciting discoveries are those that allow me to work smarter, not harder, and the article I have chosen for this month's Research Tuesday falls into that category. It is, of course, convenient (and smart and efficient) to choose an article that helps me think about a student I am trying to figure out right now, this week. But generally the evaluations that require the most time and energy are those where I find conflicting evidence, e.g. my observations, the oral language sample, and results from standardized testing don't all tell the same story. This article sheds some light on one possibility that might explain this. 

The Details: Jamie Mahurin Smith, Laura Segebart DeThorne, Jessica A. R. Logan, Ron W. Channell, Stephen A. Petrill; Impact of Prematurity on Language Skills at School Age. J Speech Lang Hear Res 2014;57(3):901-916. Retrieved November 11, 2014, from

The Question: The authors of this article review the literature linking premature birth (birth prior to 32 weeks gestation) to behavioral and emotional problems, including ADHD and deficits in executive function. Performance on standardized language measures has also been observed to be on the lower end of the normal range. These researchers questioned the reliance on scores from standardized tests and the relative lack of data from language samples in this population. So they asked how children born prematurely would perform compared to their full-term peers on standardized tests and on discourse-level language samples. They also looked at the effects of potential moderating factors, such as gender, breastfeeding, and parental education. 

The Method: Data for the study came from the Western Reserve Reading Project (WRRP), which is a longitudinal, population-based twin study. Children were selected for the premature group if they were born prior to 32 weeks gestation or if they weighed less than 1500g at birth. A second group of children born at 37 or more weeks’ gestation  was selected from the WRRP database to act as the control group. The study looked at recorded language samples from annual home visits when the children were aged 7, 8, and 10. The samples were analyzed with a variety of semantic and syntactic measures. Composite IQ scores and performance on four CELF-4 subtests and the Test of Narrative Language (TNL) were also compared between the two groups

The Results: Consistent with other studies, this study found that school-age children born prematurely scored, on average, in the lower end of the normal range and were out-performed by peers born at full term. However, in contrast to prior studies, this study documented a difference between outcomes on standardized tests and outcomes of discourse-level measures. Though differences never reached statistical significance, control children outscored the premature children on more than 90% of the measures assessed. No effect was documented for either gender or breastfeeding as a moderating factor, though parental education was associated with a generally positive effect.

The Take-Away: The current study corroborates existing findings that children born prematurely score slightly below their school-age peers on standardized tests, but within the normal range. However, these student's discourse-level language is virtually indistinguishable from those same peers. Why is this? Why are we not seeing language sample results that reflect standardized test scores. What other factors contribute to performance on the standardized tests, besides the actual language skills? 

I think these are great questions to consider when we interpret standardized test scores from any student. All kinds of factors from attention to exectuive function skills to behavior may impact performance on a standardized test. If we are seeing discrepancies beteen langauge samples and standardized scores (or other data points like teacher or parent report), these other factors may need to be part of our discussion. 

I'm looking forward to an article that has just been accepted for future publication in JSLHR on the consequences of co-occuring ADHD on children's language impairment. Stay tuned for future Research Tuesday posts!