Aim: This study was conducted to examine the effects of breathing exercises on maternal anxiety, well-being, and infant stress.
Materials and Methods: The research was initiated in a hospital in eastern Turkey between November 2024 and November 2026, after obtaining ethical committee and institutional approvals. The study population consisted of mothers whose babies were hospitalized in the neonatal intensive care unit (NICU) of that hospital.The generally available G\*Power 3.1.9.7 for Windows software was used to calculate the sample size. Similar literature studies were referenced when determining the sample size of the research (Shamsdanesh et al., 2023). Furthermore, after the research is completed, a post-hoc power analysis will be performed on the main dependent variable, maternal anxiety level (MAL), to determine the power of the study (approximately 35 experimental, 35 control). The aim of the research is to ensure that the resulting sample size has sufficient statistical power to reveal the effect being examined. The research data is collected using a Demographic Information Form, prepared by the researcher through a literature review, the State and Trait Anxiety Inventory, the Psychological Well-being Scale, and the Neonatal Stress Scale. Mothers perform this exercise three times a day for two days (days 1 and 2), under the supervision of a researcher. The four-square breathing exercise is a non-pharmacological pain reliever that has been shown to be beneficial in conditions other than pain. Each breathing exercise lasts 5-10 minutes. Mothers in the experimental group are given a questionnaire before the start of the study and after the exercise on days 1 and 2. Mothers in the control group are given only a questionnaire before the start of the study, at the end of day 1, and at the end of day 2. Mothers in the control group do not perform the four-square breathing exercise and receive routine hospital care. At the end of both days, mothers in the control group who wish to practice the breathing exercise are given the opportunity to do so.