Pain relief interventions in invasive interventions are divided into two pharmacologic methods and non-pharmacologic methods. Nonpharmacologic interventions are an area where nurses can easily demonstrate their independent roles. Especially today, when the use of complementary and alternative medicine (CAM) methods is increasing, nurses are also turning to these methods.

Non-pharmacological methods include listening to white noise, non-nutritive sucking, aromatherapy applications, placing the baby on the mother's lap, changing position, rocking, touching, distracting, listening to music, watching cartoons, singing, breastfeeding and giving sucrose solution with breast milk, giving toys and smelling mother odour.

This study was planned to determine the effect of the therapeutic toy used during IV catheter placement, which is the most common invasive intervention in the Neonatal Care Unit where a newborn baby is hospitalized, on the comfort level, crying time and physiological parameters of the newborn.

Comfort is defined as "the expected result with a complex structure within biopsychosocial and environmental integrity in order to provide help, peace of mind and cope with problems related to one's needs". According to Kolcaba, comfort is the experience of relief, peace of mind and meeting needs to solve problems. The term comfort has been frequently used in recent years for infants receiving health care in Neonatal and Neonatal Surgery Intensive Care Units. Physical characteristics of the clinic, immaturity of newborns, frequent routine care and invasive procedures (burn dressing, hydrotherapy, blood collection, IV catheter insertion, heel prick, aspiration, nasogastric catheter insertion, foley catheter insertion, rectal tube insertion, neonatal eye examination) cause a decrease in the comfort of newborns.

As a result of rapidly increasing technological developments, changes are also seen in the neonatal discipline and perinatal mortality rates are decreasing, especially in developing countries. As a result of this development, survival rates of very low birth weight newborns have increased to 85%. Although mortality has decreased in preterm infants, neurodevelopmental, pulmonary and cardiac problems have increased. When the causes of neurodevelopmental problems in preterm infants are examined, it is seen that in addition to retinopathy, systemic infections, nutritional problems due to necrotizing enterocolitis and similar causes, intracranial haemorrhage, there are also stressors such as invasive procedures, pain, noise and light that the newborn is exposed to in the intensive care unit. Stress has negative effects on neurodevelopment.

Newborns who have not reached neurodevelopmental maturity begin to experience stress when they leave their warm, dark, quiet and calm environments that contribute to their brain development and start to receive health care in intensive care units where they are exposed to noisy, light and painful procedures. This stress and invasive sensory experiences are thought to suppress the development of cell migration, synaptogenesis, myelinization and organizational structures in the infant's nervous system.

Inclusion Criteria:

• Parent's approval to participate in the study
• Born older than 24th gestational week
• The baby is hospitalized in the Neonatal Intensive Care Clinic
• Need for opening an IV catheter
• A saturation value above 90% before the invasive procedure
• Heart rate between 120-160 beats/min before the invasive procedure
• Respiratory rate between 30-60 breaths/min before invasive procedure
• Ability to open an IV road on the first attempt

Exclusion Criteria:

• The parent is not willing to participate in the study
• The baby is taking any medication that affects the comfort level
• Being monitored with mechanical ventilation
• Failure to open an IV road on the first attempt