The research was planned as a randomized controlled study to investigate the effect of breast milk smell and mother's smell applied while heel blood was taken to term babies in the Mersin City EAH Neonatal Intensive Care Unit between October and December 2023, on acute pain and crying duration. During the heel prick procedure, which is routinely performed in the neonatal intensive care unit, no pharmacological/non-pharmacological method will be applied to the control group to reduce the baby's pain before, during and after the heel prick. The baby's pain score will be evaluated by the observing nurse according to the NIPS pain scale 5 minutes before, during and 5 minutes after the procedure.

In the study group that will be made to smell the mother's scent; The mother of each baby whose heel blood will be taken will be given a specially made cover made of 100% cotton yarn, sterilized the day before, and the mother will be asked to put the cover on her bare skin (on her bare skin) after the shower and to keep the cover on the mother's chest for one night (8 hours). It will be placed 15 cm away from the baby and smelled 5 minutes before and 5 minutes after the heel prick attempt. The baby's pain score will be evaluated by the observing nurse according to the NIPS pain scale 5 minutes before, during and 5 minutes after the procedure.

The research was planned as a randomized controlled study to investigate the effect of breast milk smell and mother's smell applied while heel blood was taken to term babies in the Mersin City EAH Neonatal Intensive Care Unit between October and December 2023, on acute pain and crying duration.

The population of the research will consist of all-term babies followed in the Mersin Şehir EAH neonatal intensive care unit.

As a result of Power analysis (G*Power 3.1.9.2) based on Akcan and Polat's (2015) study titled "The effect of breast milk, amniotic fluid and lavender scent on pain during invasive procedures in newborns"; In the evaluation made according to the NIPS score, when the Effect Size was taken as 0.619, the minimum number of samples for each group determined for Power: 0.95 was determined as 28 newborns. Considering the case losses, it was planned to include 30 newborns in each group.

Randomization: In the study, 60 newborns in the sample will be randomly assigned to the control and breast milk scent groups. Random assignments will be made using a computer program to determine the group in which the newborns will be placed (https://www.randomlists.com/team-generator).

During the heel prick procedure, which is routinely performed in the neonatal intensive care unit, no pharmacological/non-pharmacological method will be applied to the control group to reduce the baby's pain before, during, and after the heel prick. The baby's pain score will be evaluated by the observing nurse according to the NIPS pain scale 5 minutes before, during and 5 minutes after the procedure.

In the study group that will be made to smell the mother's scent; The mother of each baby whose heel blood will be taken will be given a specially made cover made of 100% cotton yarn, sterilized the day before, and the mother will be asked to put the cover on her bare skin (on her bare skin) after the shower and to keep the cover on the mother's chest for one night (8 hours). It will be placed 15 cm away from the baby and smelled 5 minutes before and 5 minutes after the heel prick attempt. The baby's pain score will be evaluated by the observing nurse according to the NIPS pain scale 5 minutes before, during and 5 minutes after the procedure.

In the study group that will be made to smell the scent of breast milk, the procedures for the scent of the mother will be carried out in the same way, and 20 drops of each baby's own mother's milk will be dropped onto the diaper. The cover, which has the scent of breast milk, will be placed 15 cm away from the baby and allowed to smell it from 5 minutes before to 5 minutes after the heel prick blood collection attempt. The baby's pain score will be evaluated by the observing nurse according to the NIPS pain scale 5 minutes before, during and 5 minutes after the procedure.

During the study, all factors that may affect the pain level of babies in the intervention and control groups will be standardized. In this context, attention will be paid to factors such as ensuring that the procedure is performed when the baby is not crying, applying a 2-minute waiting period if the baby is crying, and ensuring that the heel blood is taken by experienced and always the same nurse.

Inclusion Criteria:

• Term newborns receiving treatment in Mersin City Training and Research Hospital Neonatal Intensive Care Service,
• Postnatal 1-15. Newborns on their day,
• Newborns who have not previously used any pharmacological or non-pharmacological method for pain management,
• Newborns with an Apgar score of 8 points or more at the 1st and 5th minutes,
• Not having undergone a surgical procedure,
• Does not have any health problems,
• Patients whose families approve the informed consent form.

Exclusion Criteria:

• Born before 37 weeks of gestation, receiving treatment in the Neonatal Intensive Care Service at Mersin City Training and Research Hospital,
• Sedation area
• Except for major congenital anomaly
• Older than the 15th postnatal day,
• Having a major anomaly or disease detected antenatally,
• Patients with comorbid diseases such as perinatal asphyxia, bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, congenital heart disease and similar diseases,
• Patients whose families do not give consent will not be included in the study.