Correcting for prematurity with the Bayley Scales of Infant Development.

Parents frequently ask when their infant born preterm will catch up with term peers in relation to neurodevelopment. It is well known that infants born preterm (especially those born at lower gestational age) tend to have lower scores on developmental tests compared to those born at term. In order that performance is not underestimated in early assessments, it is common practice to correct for prematurity up to 2 to 3 years. The American Academy of Pediatrics recommends an age correction for infants born preterm up to 3 years of age,1 as beyond this age the difference between corrected and uncorrected developmental quotient scores become insignificant. The need to correct for prematurity is, however, still controversial. On one hand, there is concern that applying the corrected age for too long may mask the early recognition of possible developmental deviance and delay access to educational support.2, 3 On the other hand, not correcting for prematurity may lead both to underestimating preterm abilities and possibly to unnecessary referrals, causing anxiety for parents.2, 3 Most studies to date have focused on general cognitive outcome and the fact that the effect of correction may differ across multiple developmental domains. There has been increasing evidence that rather than making general statements about correction or the age when corrections should not be used any longer, more attention should be paid to other factors, including gestational age or the specific developmental areas that may present different profiles even before the age of 2 years. Morsan et al.4 report for the first time on the appropriateness of the use of the corrected age for prematurity, exploring all the developmental domains of the Bayley Scales of Infant Development, Third Edition (Bayley‐III) and focusing on infants assessed at 12 months. They conclude that even at 12 months, the age correction for prematurity in low‐risk infants born preterm should be applied differently in the cognitive, language, and motor domains. The findings provide an important insight regarding the neurodevelopmental assessment at early ages in infants born preterm. Cognitive scores should be corrected in infants born preterm as corrected scores follow the same trend observed in infants born at term. In contrast, there is less need to correct scores for the motor domain, as uncorrected scores are already like those found in infants born at term. The results were more variable for the language domain, not allowing for a clear indication. These results therefore suggest that there is a higher need for correction when cognitive abilities are considered. While these results are important, caution should be used as only 12‐month data were considered. Several studies have reported that major motor developmental milestones that occur after the age of 12 months (such as walking, running, etc.) are delayed in infants born very preterm, sometimes even when using the corrected age. In contrast, the need to correct even at 12 months for the cognitive scores is well supported by the literature, even beyond the first year. In our experience, infants born preterm already show a delay in maintaining visual attention and in visuoperceptual tasks in the first year, confirming the uneven profile of maturation of specific aspects. For some of these aspects (mainly related to visual attention), a delay can be found even after the age of 3 years.5 The study by Morsan et al.4 lays the groundwork for future research. We hope that there will be further follow‐up to establish if their findings hold true when the infants are older. This would also allow us to establish the predictive accuracy of corrected age versus uncorrected age Bayley‐III scores for later outcome.