Sucrose will be administered 2 minutes before the puncture following the current protocol of the unit. Venous or arterial puncture will be performed only in case it is required for therapeutic or care purposes.

The administration of the sucrose dose is started by means of a syringe. Once 50% of the dose has been administered, puncture will be performed. The remaining 50% will be administered during the puncture. The pacifier will be left in the mouth until the end of the procedure, facilitating the non-nutritive sucking of the neonate.

According to the age of the newborn:

24-26 weeks : 0.1 mL, 27-31weeks : 0.25 mL, 32-36 weeks : 0.5 mL, >37 weeks : 1 mL

The primary variable is pain, and will be measured by the Premature Infant Pain Profile-Revised (PIPP-R) scale. The score ranges from 0 (no pain or minimal pain) to 21 (maximum pain).