Studies examining sleep and developmental parameters in infants have primarily focused on either term or extremely preterm infants. However, a review of the existing literature reveals a lack of research investigating sleep characteristics and their relationship with motor and sensory development in late preterm infants. Therefore, the present study aims to evaluate sleep characteristics and explore their association with motor development and sensory processing in late preterm infants, who are at higher risk for developmental delays compared to term infants.

Late preterm infants are defined as those born between 34 and 36 weeks and 6 days of gestational age. Although the medical literature places significant emphasis on extremely low birth weight and extremely preterm infants, late preterm infants are also at risk, with mortality rates three times higher than those of term infants. Born with lungs and brains that are not yet fully matured, late preterm infants may experience complications due to immaturity. Although they often appear healthier and more mature than they are, late preterm infants show significant differences from term infants (born between 37 and 42 weeks of gestation), particularly because their brain development has not yet been completed.

During the final weeks of gestation (34-40 weeks), critical developmental processes occur in the brain, including the formation of synaptic connections, myelination, and the development of cortical folds. Compared to normal term neonates, the late preterm brain appears 20% to 30% smaller, less developed, and less myelinated on magnetic resonance imaging. The sensory system is shaped immediately after birth by both the quantity and type of sensory experiences and continues to develop throughout life. In preterm infants, sensory processing has been associated with immaturity at birth, length of stay in the neonatal intensive care unit, white matter injury, and caregiver education.

Sleep is a critical factor for the healthy development of processes such as brain maturation, motor planning, postural control, and sensory integration, especially during infancy. Sleep is closely linked to brain development and infant behavior, and disruptions in sleep patterns can have profound and long-term effects on an infant's overall health, growth, and well-being in early life. Moreover, sleep plays a crucial role in the formation of persistent neural circuits necessary for early sensory development and the maturation of primary sensory systems in infants. The aim of this study is to investigate the relationship between sleep characteristics and motor development and sensory processing skills in late preterm infants (born between 34 weeks and 36 weeks + 6 days of gestation) who are between 6 and 12 months of corrected age. It is thought that sleep problems, which are frequently observed in preterm infants, may have significant effects on motor and sensory development. In this context, the primary objective of the study is to elucidate how sleep patterns and characteristics are associated with motor and sensory development in late preterm infants, and to provide scientific evidence to inform early intervention programs.

Inclusion Criteria:

• Late preterm infants with a corrected age of 6-12 months,
• Infants with parental consent

Exclusion Criteria:

• Infants with chromosomal abnormalities,
• having serious congenital problems,
• whose parents are unwilling to work,

The study group will consist of late premature babies (34-36 weeks) and their families whose corrected gestational age is between 6-12 months and whose parents' consent has been obtained.