Apnea of prematurity is one of the most common complications in preterm infants hospitalized in neonatal intensive care units. This randomized controlled trial was conducted to evaluate the effect of maternal odor exposure as a developmental care intervention on apnea frequency, physiological parameters, and growth outcomes in preterm infants. Sixty preterm infants were randomly assigned to either a maternal odor intervention group or a routine care control group. The intervention group received maternal odor using a cotton cloth carrying the mother's natural scent for five consecutive days. The primary outcome was the daily number of apnea episodes. Secondary outcomes included oxygen saturation, heart rate, respiratory rate, body temperature, weight, and head circumference.

Apnea of prematurity is a frequent complication of preterm birth and is associated with intermittent hypoxemia and adverse clinical outcomes. Developmental care interventions that provide familiar sensory stimulation may improve physiological stability in preterm infants. Maternal odor is a natural olfactory stimulus that may support autonomic regulation and respiratory stability through early sensory recognition.

This single-center, parallel-group, randomized controlled trial evaluated the effectiveness of maternal odor exposure in preterm infants admitted to the neonatal intensive care unit. Sixty eligible preterm infants were randomly assigned in a 1:1 ratio to either a maternal odor intervention group or a routine care control group. Maternal odor was provided using a cotton cloth impregnated with the mother's natural body odor, positioned approximately 10-15 cm from the infant's head for five consecutive days and replaced every 8 hours.

The primary outcome was the daily frequency of apnea episodes. Secondary outcomes included oxygen saturation (SpO₂), heart rate, respiratory rate, body temperature, weight, and head circumference. Outcomes were compared between groups to determine whether maternal odor exposure improves respiratory stability and physiological regulation in preterm infants.

Inclusion Criteria:

• Preterm infants born between 26 and 37 weeks of gestation
• Birth weight between 1000 and 2500 g
• Hospitalized in the neonatal intensive care unit for at least 5 days
• Receiving oral or enteral feeding
• Written informed consent obtained from parent(s) or legal guardian(s)

Exclusion Criteria:

• Endotracheal intubation, mechanical ventilation, or nasal continuous positive airway pressure
• Receiving oxygen therapy
• Congenital heart disease
• Suspected or confirmed sepsis
• Intracranial hemorrhage
• Receiving analgesic, sedative, or muscle relaxant therapy
• Previous surgical procedure
• Development of a medical condition requiring withdrawal from the study or hospitalization for less than 5 days

Individual participant data will not be made publicly available. The informed consent obtained from participants' parents/legal guardians did not include permission for sharing individual participant data with external researchers.

Blinding was not feasible because of the nature of the maternal odor intervention.