Preterm birth: a paradigm of sleep disruption.

Sleep is a vital neuroendocrine function undergoing numerous changes from foetal to adult life, being highly predominant during early developmental phases. Prenatal life is presumably immersed in a sleep state, crucial for development, maturation, and connectivity, thereby shaping cognitive and emotional, and experiential processes. Lifelong, sleep supports optimal growth, coupling of central and autonomic nervous systems, brain repair, and immune regulation.Preterm birth interrupts foetoplacental communication, altering both prenatal brain development and foetal sleep homeostasis. Neuroinflammation, long-term neurological and neurodevelopmental issues -including psychiatric illness and sleep disturbances- are well-known outcomes of prematurity, where a neglected contributor, sleep loss, may play a crucial role.This review argues that wakefulness is absent during prenatal life, with sleep being the constant foetal behavioural state, and that prematurity may be a paradigm of early sleep loss. Our viewpoint may inspire potential future research and guide innovative therapeutic strategies.