The Effect of Four Different Methods Used During Body Weight Measurement in Newborns on Comfort and Physiological Variables

Aim: The study, planned to be conducted in a single-center, parallel-armed, randomized experimental design, aims to determine the effect of four different methods (Routine Care, Holding, Swaddling, Swaddling + Holding) on comfort scores as the primary outcome and on heart rate (HR) and peripheral capillary oxygenation (SaPO2) as secondary outcomes.

Research hypotheses

Primary Hypothesis:

H1/1: There is a difference between the mean comfort scores of the groups.

Secondary Hypothesis:

H1/2: There is a difference between the mean HR values of the groups. H1/3: There is a difference between the mean SaPO2 values of the groups.

Variables of the study: The COMFORTneo scores, HR, and SaPO2 values of newborns are the dependent variables of the study. The methods of "Routine Care," "Holding," "Swaddling," and "Swaddling + Holding" are the independent variables of the study. The sex, birth weight, current weight, gestational age, postnatal age, etc. of newborns are control variables.

Location and characteristics of the research site: The research is planned to be conducted between February 14 and 21 Mart 2026, at the Neonatal Follow-up Clinic of Mersin University Hospital, a tertiary healthcare facility. The clinic is open from 8 a.m. to 4 p.m., and routine measurements of newborns' body weight are performed as part of follow-up care.

Research population and sample: Newborns scheduled for routine body weight measurements as part of follow-up appointments will be seen at the Mersin University Hospital Neonatal Follow-Up Clinic. The sample size was determined using a priori power analysis. The effect size (d=1.17) from the study "The effect of three different methods applied during peripheral vascular access in preterm infants on pain and comfort levels" was used as the basis for the analysis. Accordingly, the required sample size was calculated as 20 newborns for each group to ensure that the difference between the comfort score averages of at least two of the groups would be statistically significant with a maximum of 5% type I error (α = 0.05) and at least 90% power (1-β = 0.90). Considering that losses may occur during the research process, the sample size was increased by 20%, and the sample size of 96 newborns was calculated, with 24 newborns in each group.

Inclusion Criteria for the Study:

• Body weight measurement is planned as part of follow-up at the Mersin University Hospital Newborn Follow-up Clinic,
• The parent gives consent for the baby and themselves to participate in the study,
• The parent's body weight is less than 100 kg,
• The newborn's birth weight is 2500 g or more,
• The newborn's gestational age at birth is less than 37 weeks,
• The newborn's postnatal age is 28 days or less,
• The newborn is physiologically stable.

Exclusion Criteria from the Study:

• The newborn has undergone surgery,
• The newborn has a genetic, metabolic, or congenital disorder,
• The newborn has a neuroendocrine disorder,
• The newborn's gestational age at birth is greater than 37 weeks,
• The newborn's postnatal age is greater than 28 days.

Randomization and blinding To maintain balance between groups, the block randomization method will be preferred. Using a simple random selection method (randomizer.org), 16 blocks will be selected from 24 different block combinations with block size 6 containing codes A, B, C, and D (AADDCCBB, DDAABBCC, DBCCAABD) to create a random assignment sequence (1-96). Each newborn will be numbered according to the order of intervention and placed in opaque sealed envelopes. Parents will be blinded to the intervention groups during the application and evaluation period. The implementer and evaluator will be blinded to the research hypotheses. Data entry, analysis, and reporting will be performed by a researcher unaware of the intervention groups using the codes A, B, C, and D. After statistical analysis is completed and the research report is written, the coding for the intervention groups will be disclosed to the relevant researcher.

Data collection tools: The Newborn Information and Observation Form and the COMFORTneo will be used to collect research data. A monitor and compatible pulse oximeter, camera, termometer and sheets as wrapping material will be used as data collection tools.

Newborn Information and Observation Form: Developed by researchers after a literature review, the Newborn Information and Observation Form consists of multiple-choice and open-ended questions. It includes questions such as the newborn's gender, birth weight, gestational age at birth, postnatal age, and whether they experienced procedural pain in the last 24 hours prior to the procedure etc.

Comfort Scale (COMFORTNeo): TIt is a Likert-type scale consisting of six parameters: alertness, calmness/agitation, respiratory response, crying, body movements, facial tension, and muscle tone. In newborns receiving mechanical ventilator support, the "Respiratory Response" item is evaluated, while in those not receiving mechanical ventilator support, the "Crying" item is evaluated. Each item on the scale is scored from 1 to 5. It is evaluated based on the total score. The lowest possible score on the Neonatal Comfort Behavior Scale (NCBS) is 6, and the highest possible score is 30. If the total scale score is between 14 and 30, it is emphasized that the infant is in pain or distress, is uncomfortable, and requires interventions to provide comfort.

Monitor and Pulse Oximeter: The monitor located in the outpatient clinic and the compatible pulse oximeter sensor will be used for measuring the newborn's heart rate (beats/min) and SaPO2 (%) before, during, and after the procedure.

Camera: A portable tablet will be used to record video throughout all stages of the procedure, capturing "the baby's face and behavior" and "the HR and SaPO2 values on the monitor."

Thermometer: It will be used to monitor the body temperature of newborns before, during, and after procedures to assess the safety of interventions.

Preliminary application and implementation of the study: The application steps will be performed on a mannequin before research data collection begins. Subsequently, a pre-application will be performed on 4 newborns who are not included in the research but for whom routine body weight measurement is planned. The parents of newborns who meet the inclusion criteria will be informed about the purpose and process of the study, and the participant information and consent form will be read to them. Written consent will be obtained from parents who wish for their baby and themselves to participate in the study.

The information on the Neonatal Information and Observation Form (gender, birth weight, gestational age at birth, postnatal age, experience of procedural pain in the last 24 hours prior to the procedure, sleep-wake status) will be completed by the evaluator from the file 10 minutes before the procedure, after obtaining written consent from the parent. Video recording will begin 7 minutes before the procedure, and a pulse oximeter will be placed on the newborn's right palm. The camera angle will be adjusted so that "the baby's face and behavioral responses can be seen" and "the KAH and SaPO2 values on the monitor can be read." The practitioner will remove the newborn's clothing, leaving only the diaper on, and attach the pulse oximeter probe to the palmar area of the right hand. Video recording will continue for 5 minutes after all procedures are completed. During this time, the evaluator will record the newborn's body weight, comfort before, during, and after the procedure, and KAH and SaPO2 values on the Newborn Information and Observation Form. The comfort score measured during the procedure will be considered indicative of the stress response, while the comfort scores at 1 and 2 minutes after the procedure will be considered indicative of stress regulation. The video recordings will be sent to a second evaluator who is a certified neonatal nurse for COMFORTneo and a scientific expert.

Implementation of Procedures:

Routine care: Resetting the scale, safely placing the newborn on the baby scale, weighing, and removing from the scale Swaddling: Swaddling the newborn using a safe technique, resetting the scale, safely placing the newborn on the baby scale, weighing, and removing from the scale Holding: Safe holding of the newborn by the parent, resetting the scale, weighing the newborn on an adult scale while held by the parent, and weighing only the parent on the adult scale Swaddling + Holding: Swaddling the newborn safely, the parent safely holding the newborn, resetting the scale, weighing the newborn on the adult scale while in the parent's arms, only the parent stepping on the adult scale and being weighed.

Data analysis and evaluation: Statistical package programs will be used in data analysis and visualization of results. The statistical significance level will be set at ≤0.05. Depending on whether the scale scores show a normal distribution, parametric or non-parametric tests will be used to compare differences between means according to interventions.

Ethical considerations of the study: The necessary permissions for the Turkish version of the comfort scale to be used in the data collection process have been obtained via email. Ethical approval will be obtained from the Mersin University Rectorate Clinical Research Ethics Committee and written institutional permission will be obtained from Mersin University Hospital for the study. The research protocol will be prospectively registered on clinicaltrials.gov. Information will be provided on the purpose, duration, and implementation of the research, and written consent will be obtained from the parents of newborns for both their babies (Legal Representative Informed Consent Form) and themselves (Adult Informed Consent Form).