Early delayed language development in very preterm infants: evidence from the MacArthur-Bates CDI.

This study examined the effects of being born very preterm on children's early language development using prospective longitudinal data from a representative regional cohort of 90 children born very preterm (gestational age <33 weeks and/or birth weight <1,500 grams) and a comparison sample of 102 children born full term (gestational age 38-41 weeks). The MacArthur-Bates Communicative Development Inventory: Words and Sentences (CDI-WS) was used to assess children's language development at age 2;0 (corrected for gestational age at birth). Clear linear relationships were found between gestational age at birth and later language outcomes, with decreasing gestational age being associated with poorer parent-reported language skills. Specifically, children born extremely preterm (<28 weeks' gestation) tended to perform less well than those born very preterm (28-32 weeks' gestation), who in turn performed worse than children born full term (38-41 weeks' gestation). This pattern of findings was evident across a range of outcomes spanning vocabulary size and quality of word use, as well as morphological and syntactic complexity. Importantly, associations between gestational age at birth and language outcomes persisted after statistical control for child and family factors correlated with both preterm birth and language development. These findings demonstrate the presence of pervasive delays in the early language development of children born very preterm. They also highlight the importance of gestational age in predicting later language risk in this population of infants.