Objective: To examine the language development at corrected age 4 years of a regionally representative cohort of children born very preterm (VPT). Of particular interest was the identification of biological and socioenvironmental risk and protective factors that influence VPT children's early language development.
Method: Data were collected as part of a prospective longitudinal study of 110 VPT (VPT: ≤ 33 weeks gestation) and 113 full-term children (full term: 37-41 weeks gestation) born in Canterbury, New Zealand from 1998 to 2000. At corrected age 4 years, all children were assessed with the preschool version of the Clinical Evaluation of Language Fundamentals. Extensive information was also collected about children's family social background, perinatal health, childrearing environment, education/intervention exposures, and neurodevelopmental progress from birth to age 4.
Results: At the age of 4 years, VPT children were characterized by poorer receptive and expressive language development than full-term children. These differences persisted after exclusion of children with neurosensory impairment as well as statistical adjustment for the effects of social risk. Within the VPT group, the key predictors of children's overall language development were family social risk at birth (p =.05), severity of white matter abnormalities on neonatal magnetic resonance imaging (p =.49), observed parent-child synchrony (p =.001), and concurrent child cognitive ability (p =.001). Together, these factors accounted for 45% of the variance in children's total Clinical Evaluation of Language Fundamentals-Preschool scores.
Conclusion: By preschool age, children born VPT show early emerging mild to moderate language delays that are likely to affect their school success and longer-term developmental progress. Findings highlight the importance of potentially modifiable factors such as early brain injury and parenting quality in predicting the language outcomes of children born VPT.