Is It Correct to Correct for Prematurity? Theoretic Analysis of the Bayley-4 Normative Data

Objective: To determine whether correction for prematurity is appropriate for cognitive, language, and motor function at varying degrees of prematurity and at different baseline functional levels. Methods: The newly published Bayley-4 normative data on 1700 normal children were used. Raw scores for baseline levels of function (-2 SD, -1 SD, and M) were identified at 6, 12, 24, and 36 months for receptive communication, expressive communication, fine motor, and gross motor scaled scores and cognitive, language, and motor composite scores. Differences between the baseline and uncorrected scores at 4, 3, 2, and 1 months of prematurity were evaluated at each age. Results: Using a cutoff of 3 points (1/5 SD), correction is needed for cognitive composite scores at all gestational ages for the first 2 years and in those born 4 months premature at 3 years of age; language and motor composite scores should be corrected to 3 years at all degrees of prematurity. Conclusion: Not correcting for prematurity in cognitive, language, and motor function at 3 years and younger places preterm infants at a distinct disadvantage when compared to peers with few exceptions, suggesting that such correction should be routine.