Sitting Acquisition and Early Communication Development: Are There Associations in Very Preterm Infants at Six Months of Corrected Age?

Background: Research in typically and some atypically developing populations showed associations between early motor and communication development, documenting how postural development can support communicative advancements. However, these relations have scarcely been investigated in the preterm population. Aims: The present study aimed to describe motor (gross and fine motor) and communication (receptive and expressive) skills of very preterm infants at six months of corrected age and their associations, focusing on sitting posture achievement and early vocal production. Methods: Seventy very preterm infants (≤ 32 weeks) with no major brain injuries were assessed with the BSID-III for gross and fine motor skills, receptive and expressive language skills, and cognitive skills and were categorized as mastering (sitters), partially mastering (emerging sitters), or not mastering (non sitters) unsupported sitting. The proportional duration of sitting postures (caregiver supported, arms supported, and unsupported) in an observative section was coded with the Interact software (version 20.8.3.0). Frequency per minute of vocal utterances (vocalizations, babbling, and total) during a parent-infant play interaction was coded with the CHILDES software v11. Results: Correlational analyses showed significant positive associations between motor composite score and language scores (composite and expressive scaled) and between gross motor and expressive language scaled scores but a negative association between arms supported sitting duration and vocal utterances. In addition, ANCOVAs showed that sitters had significantly higher BSID-III expressive language scaled scores and vocal utterances than non sitters and emerging sitters. Conclusions: These findings brought new evidence linking early motor and vocal development in very preterm infants, emphasizing the importance of using observational tools alongside standardized ones to identify developmental delays and plan tailored intervention programmes.