Tackling Acquisition of Language in Kids born Preterm (TALK-Preterm): protocol of a prospective cohort study.

Background: Children born extremely preterm (EPT) are at significant risk for delays in language development. Language is important for the developing child not only because of its relationship with cognition and academic performance but also because of its impact on quality of life and relationships with peers and caregivers. Late talking, which can be reflective of expressive language difficulties, is particularly common in children born extremely preterm. Preterm infants born at NICHD Neonatal Research Network (NRN) centers have historically been enrolled in the NRN Generic Database (GDB) and followed to 22-26 months corrected age to assess language, motor, and cognitive development with the Bayley Scales of Infant and Toddler Development, 4th edition (Bayley-4) as part of the NRN GDB. For this study, we are recruiting a subset of children from the GDB who were born at < 29 weeks completed gestation and assessed with Bayley-4 at 22-26 months corrected age to undergo additional language assessments, magnetoencephalography (MEG), and MRI at 3 to 4 years corrected age. We are also recruiting a cohort of term-born comparison children (TC) with typical development to undergo the same language and imaging assessments. Our overall objective is to assess the trajectory of - and neural mechanisms underlying - language delay or difficulty in extremely preterm infants, compared to a healthy full-term comparison group. Methods: The TALK-Preterm study is a prospective follow-up study of EPT infants and term-born peers at two NRN centers that leverages the perinatal and developmental phenotyping data obtained during the first 2 years of life. Children undergo a single in-person study visit at 3-4 years corrected age with multimodal neuroimaging (MEG and MRI) and assessment of language outcomes and parent-completed questionnaires. The term-born comparison group is recruited at 3-4 years and undergoes the same assessment at that time point. Discussion: The TALK-Preterm study goes beyond standard language assessments by using innovative multimodal neuroimaging to examine the neural mechanisms underlying varied language outcomes in preterm-born children versus to term-born preschool children. By characterizing language trajectories and the neural connectivity that supports language learning, the study will generate rigorous data to advance understanding of variable language outcomes in extremely preterm children and identify brain-based markers of language development that can inform future mechanistic research and promote public health.