Abstract
OBJECTIVE: It is unclear if speech input in neonatal units improves delayed language development in very preterm infants. This longitudinal study investigated whether the parents' speech in family-centered neonatal units associated with language outcomes in children born very preterm. STUDY DESIGN: The auditory environment of 82 infants born <32 gestational weeks was recorded using Language Environment Analysis at 32-34 weeks of postmenstrual age. The language environment was analyzed for the total recording time and the periods when the parents were present. Receptive and expressive language skills were measured at 1 year (MacArthur-Bates Communicative Development Inventory) and 2 years of corrected age (Reynell Developmental Language Scales III). RESULTS: Father's word frequency on recording day (b ln-scale 0.05, 95% CI 0.003-0.09, P = .04), and conversational turns with the mother during 14 days (b ln-scale 0.08, 95% CI 0.01-0.16, P = .03) were positively associated with expressive lexicon size at 1 year. Overall adult word frequency was negatively associated with the child's expressive language skills at 2 years of corrected age (b in-scale -0.13, 95% CI -0.24--0.01, P = .03). CONCLUSIONS: Parents' speech in the neonatal unit may support language development of children born preterm, whereas high total adult words - including the time when parents were not present in the unit - may impair it. Our findings should be cautiously interpreted as the associations were weak. TRIAL REGISTRATION: Auditory Environment by Parents of Preterm Infants (APPLE), registration number: NCT04826978, date of registration: 2021-03-29.