Effects of Early Vocal Contact (EVC) in the Neonatal Intensive Care Unit

Background: Preterm infants are at risk for developing altered trajectories of cognitive, social, and linguistic competences compared to a term population. This is mainly due to medical and environmental factors, as they are exposed to an atypical auditory environment and, simultaneously, to long periods of early separation from their parents. The short-term effects of Early Vocal Contact (EVC) on an infant's early stability have been investigated, but currently, there is limited evidence of its impact on the infant's autonomic nervous system maturation, as indexed by the heart rate variability, as well as on its long-term impact on infant neurodevelopment. This multi-centric study aims to investigate the effects of EVC on a preterm infant's physiology, neurobehaviour, and development. Methods: Eighty stable preterm infants, born at 25 to 32 weeks and 6 days gestational age, without specific abnormalities, will be selected and randomized to either an intervention or a control group. The intervention group will receive EVC: mothers talking and singing to their preterm infants for 10 minutes thrice a week for 2 weeks. Mothers in the control group will be encouraged to spend the same amount of time next to the incubator, observing the infant's behaviour through a standard cluster of indicators. Infants will be assessed at baseline, at the end of the intervention, at term equivalent age, and at 3, 6, 12- and 24-months corrected age, with a battery of physiological, neurobehavioral, and developmental measures. Discussion: Early interventions in the neonatal intensive care unit have shown important effects on the neurodevelopment of preterm infants, lowering the negative long-term effects of an atypical auditory and interactional environment. This study will provide new insights into the mother-infant early contact as protective intervention against the sequelae of prematurity during the sensitive period of development. An early intervention, such as EVC, is intuitive a