A Model of Neurodevelopmental Risk and Protection for Preterm Infants

Abstract

The purpose of this article is to introduce a model of neurodevelopmental risk and protection that may explain some of the relationships among biobehavioral risks, environmental risks, and caregiving behaviors that potentially contribute to neurobehavioral and cognitive outcomes. Infants born before 30 weeks of gestation have the poorest developmental prognosis of all infants. These infants have lengthy hospitalization periods in the neonatal intensive care unit (NICU,) an environment that is not always supportive of brain development and long-term developmental needs. The model supports the premise that interventions focused on neuroprotection during the neonatal period have the potential to positively affect long-term developmental outcomes for vulnerable very preterm infants. Finding ways to better understand the complex relationships among NICU-based interventions and long-term outcomes are important to guiding caregiving practices in the NICU.

Bilingualism as a Potential Strategy to Improve Executive Function in Preterm Infants: A Review

“…Because environmental stimuli mediate neurodevelopmental outcomes and actually alter the preterm brain's architecture, the brain development of a preterm infant can be modified through experiences. This claim is supported by the theory of brain plasticity, which postulates that development of neural networks depends on molecular cues, regulated by environmental stimuli, to guide synaptic formation and pruning (Johnston et al, 2009;Pickler et al, 2010). Consistent with this evidence, it should be possible to influence cognitive outcomes in preterm infants through an early intervention that promotes synaptogenesis and appropriate selective pruning.…”

“…Data from Pitcher and colleagues (2012) support this claim, because adolescents born preterm have impairments in long-term potentiation, an underlying cellular mechanism of cortical plasticity. However, an extensive line of evidence shows that long-term outcomes in preterm infants can be mediated by environmental experiences, suggesting a plastic nature to preterm infant's neurological development (Pickler et al, 2010). Exposure to adverse environmental stimuli in the neonatal intensive care unit has been found to negatively impact neurological development.…”

“…Although preterm birth interrupts this growth, time of maximal synaptogenesis and dendritic growth occurs during the first 2 years of life, suggesting a high level of plasticity and capacity to recover from injuries associated with preterm birth (Luciana, 2003). Plasticity refers to the ability of the brain to reorganize neural circuits in response to changes in environmental stimuli by modifying the number and strength of synaptic connections (Pickler et al, 2010). The most extensive plastic changes take place during the first 2 years of life as synapses are produced at a rapid rate and excess connections form (Cioni, D'Acunto, & Guzzetta, 2011;Johnston et al, 2009).…”

“…Preterm infants are subsequently put at higher risk as the result of noxious stimuli in the neonatal intensive care unit and hypoxia due to lung immaturity. Furthermore, a major risk for poor neurodevelopmental outcomes is interruption of structural differentiation and rapid growth in the brain that occurs in the third trimester (Pickler et al, 2010). Brain volume increases nearly three-fold between the gestational age of 29 weeks and 40 weeks (Huppi et al, 1998).…”

“…Studies have suggested that decreased brain volume persists throughout childhood and correlates with measures of IQ and executive functioning (Peterson et al, 2003). Given that the prefrontal cortex, which governs executive functions, matures during the last 2 months of gestation, preterm infants are particularly vulnerable to deficits in executive functioning (Pickler et al, 2010). These deficits are most prevalent and severe among children born extremely preterm (< 28 weeks) and very preterm (28 to 32 weeks), and increasing evidence demonstrates that school performance, use of special education services, and measures of executive functioning are inversely related to gestational age (Vohr, 2013;Williams et al, 2013).…”