The objective of this clinical trial is to evaluate the effect of positional restraint on the stress level of preterm newborns, resting in the incubator. The main question sought to be answered is: The stress level of the preterm newborn will decrease with swaddy® containment, compared to standard care, and both with similar safety.

Participants will remain in the incubator for 3 consecutive hours and the level of stress in the same patient will be evaluated, one day with containment and another day without containment.

Primary objective: To assess the effect of Swaddy® containment on the stress level of newborns ≤1500 grams at birth admitted to a NICU, using the Comfort B Scale, for a maximum period of 3 consecutive hours, compared to standard containment care.

Secondary objectives:

• To evaluate the effect of positional restraint with Swaddy® on the stability of the preterm newborn, through the physiological parameters HR, RF, temperature, and SatO2, compared to standard containment care for 3 consecutive hours.
• To evaluate the safety of the number of apneas, in containment with Swaddy® compared to standard care.

Swaddy®, is an adjustable garment of clothing, with a built-in cap, which favors the symmetry of limbs with midline of the body and the hand-to-hand and hand-to-mouth position of preterm newborns, very conciliatory positions for these patients. Its fabric is thin and soft, to prevent overheating, and elastic, to favor the flexor position and allow some mobility. It is a device designed by the IP of the project, registered and patented by the Institut de Recerca Sant Pau, and currently marketed.

In this project, patients will be randomized into two groups. In Group 1, on the first day (day 1), the first measurement (baseline) will be made. Subsequently, the Swaddy® containment device will be placed and the containment will be maintained for 3 hours, in which the same variables will be measured: Heart Rate (HR), Respiratory Rate (RF), temperature, O2 Saturation (SatO2) and pain scale at 60, 120 and 180 minutes. This procedure will be repeated on day 2 and 3. On day 4, the same measurements will be carried out using standard containment care. This procedure will be repeated on days 5 and 6 (all three at approximately the same time of day as in the intervention). In Group 2, it will be done in reverse.

Vital signs HR, RF, oxygen saturation will be measured with the patient's monitor and temperature with a skin sensor in the incubator itself, which will be located in the patient's thoracoabdominal area.

To assess the safety of the device, the number of apneas of prematurity performed with Swaddy® containment and standard care will be recorded.

Inclusion Criteria:

• Newborns weighing ≤1500 grams at birth admitted to the NICU. • Patients who are in an incubator.

Exclusion Criteria:

• Hemodynamic instability.

  • Be a carrier of CPAP or nasal BIPAP with a cap (because the CPAP/BIPAP already has a built-in cap, just like Swaddy).
  • Be in treatment with phototherapy.