Control group: No intervention was made except for the routine care provided at the clinic where the study was conducted. Routine practices included allowing the mother to visit and see her baby at the clinic whenever she wanted. When the mother came for the first visit, the mother and baby introductory information form, Neonatal Intensive Care Unit Parent Stress Scale, Inadequate Milk Perception Scale, Mother-Infant Attachment Scale and NICU Parental Beliefs Scale pretest were administered. On the third day, when the mothers came to visit their babies, the same scales were administered as posttest.

The infants who met the selection criteria were wrapped with OOKIE upon admission and remained in contact with OOKIE for approximately 24 hours without affecting their routine care and position. After 24 hours, when the mother came for the first visit, the mother and baby introductory information form, Neonatal Intensive Care Unit Parent Stress Scale, Inadequate Milk Perception Scale, Mother-Infant Attachment Scale and NICU Parental Beliefs Scale pretest were administered. During the visit, the mother received the OOKIE wrapped around her baby in the incubator and stayed with the mother for 3 days and the mother could smell her baby's odor whenever she wanted.

The OOKIE used in the study is a doll made of 100% cotton flannel fabric, with satin edges, 35cmx 40cm in size and produced in various colors. Due to its structure, it can be easily washed, dried and sterilized. The fabric feature is capable of trapping and transferring odor. It is a suitable tool for mothers who are separated

The infants who met the selection criteria were wrapped with OOCIE upon admission and remained in contact with OOCIE for approximately 24 hours without affecting their routine care and position. After 24 hours, when the mother came for the first visit, the mother and baby introductory information form, Neonatal Intensive Care Unit Parent Stress Scale, Inadequate Milk Perception Scale, Mother-Infant Attachment Scale and NICU Parental Beliefs Scale pretest were administered. During the visit, the mother received the OOKIE wrapped around her baby in the incubator and stayed with the mother for 3 days and the mother could smell her baby's odor whenever she wanted.

Parents were asked to rate the level of stress caused by each of the factors in the scale from one (no stressor) to five (extreme stressor). Factors with a mean score between 3.0 and 3.40 are considered moderately stressful, and factors with a mean score >3.40 are considered very stressful. Stress factors are analyzed in 3 subgroups. The first is the "Sights and Sounds" subgroup, which includes factors such as the presence of equipment on the baby or in the intensive care unit, sounds arising from them and the environment. The second is the "Appearance and Behavior of the Baby" subgroup, and the third is the factors related to the "Role of the Parents". While filling in the statements such as the presence of tubes and other equipment on or near the baby, sudden change in the baby's color or the baby's breathing stopping, mothers whose babies did not have these symptoms did not mark these items.

The inadequate milk perception scale is a form consisting of 6 questions. In the first question, the mother is asked whether she believes that she is feeding her baby enough. The mother answers this question as "yes" or "no". The other questions of the scale aim to measure the perception of milk insufficiency. The mother is asked to score these questions between 0-10. "0" indicates that milk is perceived as completely inadequate and "10" indicates that milk is perceived as completely adequate. A minimum score of 0 and a maximum score of 50 can be obtained from the scale. A higher total score indicates a higher perception of milk adequacy. In the original scale, Cronbach α value was determined as 0.81.

The scale is designed to be applied from the first day after birth and allows the mother to express her feelings towards her baby with a single word. The Mother-Infant Attachment Scale (MICS) is a 4-point Likert scale consisting of 8 items. The responses consisting of four options are scored between 0-3, with the lowest score being 0 and the highest score being 24. In the evaluation, items 1, 4, and 6 are positive emotion expressions and are scored as 0,1,2,3, while items 2, 3, 5, 7, and 8 are negative emotion expressions and are scored as 3,2,1,0.