Neurodevelopmental consequences of preterm birth: Dysfunction or adaptation? How postnatal stress impacts variation in neonatal brain development

There are few experiences as trying as preterm birth. For both the parent and the child, the first few weeks of life are mired by uncertainty, adversity, and (subjective) stress. The complex and diverse effects of postnatal stress affect many highly correlated (immature) biological systems following preterm birth. Many of the stressful interventions are clinically necessary and are usually unavoidable. Hence, one of the critical aspects is to investigate (i) how postnatal stress affects the emerging, still developing brain and (ii) motivated by the significant inter-individual differences in outcome, which infants might be at risk, or resilient, for later mental health issues.

Previous studies have suggested that stress may lead to delayed brain development and deficits in preterm-born infants. However, recent research proposes a more nuanced theory, suggesting that adaptation to adversity might involve accelerated maturation of specific brain networks related to fear learning and responses to stressful environments, with potential costs in cognitive control.

An essential part of this thesis was founded on the evolutionary-developmental perspective of stress acceleration, in which we argue that postnatal stress might invoke context-dependent adaptability. The research in this thesis illustrates that prematurity is characterized by the accelerated development of large-scale brain networks and informs us of the clinical value of neonatal brain alterations. Resilient infants are less affected by the degree of postnatal stress, as indicated by the preservation or adaptation of specific connections, which might be due to potential compensatory mechanisms or an innate ability to cope well with early life stress. Our findings provide evidence for the hypothesis that preterm birth is not merely characterized by deficits but also a context-dependent adaptation or even "hidden talents" (i.e., adaptive developmental processes, such as social and cognitive skills, that develop in response to a harsh and unpredictable environment). These findings may give rise to a shift in the conceptual framework, potentially moving from a disease perspective toward a stress-adaptation perspective. In this Chapter, I reflect on our methodological choices, the translation to intervention and prevention, and possibilities for future research.