After birth, fetal erythrocytes in the newborn are rapidly destroyed and the total bilirubin level increases, resulting in hyperbilirubinemia. Hyperbilirubinemia; although it is a common condition that usually occurs physiologically in newborns, it causes neurological dysfunction in the newborn when it reaches high bilirubin levels. Therefore, follow-up and treatment are important. One of the treatment approaches for hyperbilirubinemia is phototherapy.

Phototherapy treatment is applied to babies diagnosed with hyperbilirubinemia by directly giving light energy to the babies. While receiving phototherapy, the baby becomes stressed due to reasons such as the mother not being able to hold her baby in her arms, not being able to breastfeed, the baby being in a different environment such as the neonatal intensive care unit, and being exposed to invasive procedures. Individualized developmental care practices accordingly, many practices are recommended in neonatal intensive care units to reduce the stress of babies. One of these practices is non-nutritive sucking. The most commonly used method for non-nutritive sucking is the use of a pacifier. It is stated that the use of pacifiers helps the baby calm down and reduces stress in neonatal intensive care units. In 1990, the World Health Organization and the United Nations International Children's Emergency Fund determined the "Ten Steps to Successful Breastfeeding" principles for the Baby-Friendly Hospital Initiative to promote and support breastfeeding. It has been noticed that in these principles rejecting the use of pacifiers, intensive care environments where the baby is stressed and situations where the mother and the baby are separated are ignored, so it has been suggested that this situation should be brought back to the agenda. In 2013, the "Ten Steps to Successful Breastfeeding" application was revised; Considering the justified reasons for the special situations in which the newborn and the mother and the baby are separated and the situations in which the baby is stressed, the newborn The use of pacifiers has been recommended in intensive care units. Considering the 24-hour treatment period during phototherapy, the baby is separated from the mother, albeit intermittently, while receiving phototherapy. In addition, the baby is in a different environment such as the neonatal intensive care unit and is exposed to invasive procedures. All of these create stress in the baby, and pacifiers are recommended for such justified reasons. The benefits of pacifier use have been proven in neonatal intensive care units, such as calming the baby, making it easier to fall asleep, and reducing pain and stress. Another benefit of non-nutritive sucking is on the gastrointestinal system. Non-nutritive sucking stimulates oro-motor development, facilitates the development of sucking behavior and facilitates digestion in enteral feeding.

A number of enzymes and hormones are involved in facilitating digestion through non-nutritive absorption. These enzymes and hormones; lingual lipase, gastrin, insulin and motilin. Experts believe that non-nutritive sucking causes this effect through vagal stimulation of the oral mucosa. It is thought that it causes the secretion of enzymes and hormones. Non-nutritive sucking in a study reported that the use of pacifiers, one of the methods, stimulates the stomach motor functions and this facilitates the digestive process through the activation of vagal mechanisms.