Circadian-Synchronized Breast Milk Feeding and Sleep in Preterm Infants: A Multicenter Randomized Controlled Trial

This clinical trial aims to find out whether a circadian-synchronized breast milk feeding approach can help improve sleep in preterm infants in the neonatal intensive care unit (NICU). The study mainly aims to answer the following questions: Can this feeding approach improve sleep in preterm infants? Can this feeding approach help preterm infants develop more regular sleep patterns compared with routine breast milk feeding? Researchers will compare a feeding approach that tries to match the time when breast milk was expressed with the time when the baby is fed, with routine breast milk feeding, to see whether this method can improve sleep in preterm infants. Participants will: Be randomly assigned to 1 of 2 groups: circadian-synchronized breast milk feeding or routine breast milk feeding. Receive the assigned feeding approach for at least 2 weeks during the study. Have one 12-hour continuous sleep monitoring session at 37 weeks of corrected age. Have changes in different sleep states recorded and analyzed during the study, so that sleep patterns can be compared between the 2 groups.

Inclusion Criteria: * Preterm infants born between 28 weeks and 36 weeks plus 6 days of gestation. * Infants who have reached full enteral feeding. * Written informed consent signed by a legal guardian. Exclusion Criteria: * Need for invasive respiratory support, such as endotracheal intubation. * Use of sedatives or other medications that may affect the central nervous system or sleep rhythm. * Presence of congenital neurologic or chromosomal abnormalities. * Presence of congenital gastrointestinal malformations or anorectal malformations. * Conditions affecting digestion or absorption, such as diarrhea, intestinal obstruction, or necrotizing enterocolitis. * Critical illnesses such as patent ductus arteriosus, neonatal sepsis, neutropenia, or coagulation disorders.