The Longitudinal Impact of Early Relational Contact in the NICU and the Post-Discharge Childcare Quality on Preterm Infants' Behavioural Development up to 18–24 Months of Corrected Age

To evaluate the associations between parental/family early relational contact in the neonatal intensive care unit (NICU) and the post-discharge childcare quality and behavioural development up to 18–24 months of corrected age (CA). In a longitudinal cohort study (2017–2022), 215 preterm infants were followed. Early relational NICU contact (minutes/day) was measured daily using a 12-item observational checklist. Post-discharge childcare quality was assessed at 18–24 months with the Index of Child Care Environment (ICCE). Behavioural development was assessed using the Bayley Scales of Infant Development III and the Brief Infant-Toddler Social and Emotional Assessment. Multiple regression models examined the associations between these key variables, adjusting for clinical and demographic confounders. The cohort was predominantly male (57.67%), non-Hispanic (74.88%) and White (67.44%), with an average gestational age of 28.3 weeks. At 18–24-month CA, greater early skin-to-skin/soothing contact was linked to better language development (β = 0.33, p = 0.032), and integrated nurturing contact (characterised by holding combined with verbal interaction) was associated with better language and motor development in female infants (p's < 0.05); strong social support for caregivers was associated with infants' improved cognitive (β = 0.364, p = 0.018), language (β = 0.383, p = 0.008) and motor (β = 0.382, p = 0.015) outcomes. Infants with typical social–emotional competence received higher levels of human stimulation from their caregivers compared with those showing possible competence issues (OR = 1.439, p = 0.020). Greater early NICU contact and higher post-discharge childcare quality are associated with improved developmental outcomes in preterm infants at 18–24 months CA, showing the growing importance of environmental factors in infants' development. Future studies should explore targeted interventions that enhance early bonding and empower parents to support sustained developmental progress.