This study is designed as a randomized controlled trial (RCT) focused on improving breastfeeding outcomes among primiparous mothers in the postpartum period. Although the World Health Organization (WHO) recommends exclusive breastfeeding for the first six months as the ideal nutritional source for newborns, the rate in Turkey (41% according to TDHS 2018) lags behind global targets (50-70%). Early cessation of breastfeeding is generally associated with mothers' inability to adapt to physical and psychological challenges. In particular, anxiety and stress experienced during the postpartum period lead to the development of a perceived insufficient milk supply, which negatively affects the acquisition of breastfeeding self-efficacy. In this context, this study investigates the potential of a supportive intervention facilitating stress management and relaxation on breastfeeding sustainability. Participants will be randomized into three groups: Intervention Group I (Online Breastfeeding Education + Breath-Based Yoga), Intervention Group II (Online Breastfeeding Education Only), and the Control Group (Routine Care). The interventions will be delivered remotely via Google Meet over a maximum period of seven weeks (3 weeks of breastfeeding education + 4 weeks of yoga practice). The primary objective of the study is to evaluate whether these structured interventions significantly improve maternal breastfeeding self-efficacy and reduce the perception of insufficient milk. Additionally, secondary outcomes will assess the impact on maternal anxiety levels. To ensure internal validity and isolate the intervention effect, mothers at high risk of postpartum depression (EPDS score > 13) are excluded from the study.

The Hypotheses of the Study

Each hypothesis will be tested independently:

H₀: The pre- and post-intervention measurement differences do not significantly differ between groups.

H₁: The pre- and post-intervention measurement differences significantly differ between groups (p < 0.05).

If a significant difference is detected, H₀ will be rejected and H₁ will be accepted. Multiple comparisons will be evaluated using the Holm-Bonferroni correction to control the Type I error rate.

• H1a: Online breastfeeding education provided to primiparous mothers positively affects their anxiety levels.
• H1b: Online breastfeeding education provided to primiparous mothers positively affects their breastfeeding self-efficacy.
• H1c: Online breastfeeding education provided to primiparous mothers positively affects their perceived insufficient milk supply.
• H2a: Breath-based yoga-supported online breastfeeding education provided to primiparous mothers positively affects their anxiety levels.
• H2b: Breath-based yoga-supported online breastfeeding education provided to primiparous mothers positively affects their breastfeeding self-efficacy.
• H2c: Breath-based yoga-supported online breastfeeding education provided to primiparous mothers positively affects their perceived insufficient milk supply.

Background Breast milk is the most ideal source of nutrition for newborns, due to its essential nutrients and bioactive components. The WHO recommends exclusive breastfeeding for the first six months, aiming for a rate of 50% by 2025 and 70% by 2030. Breast milk reduces morbidity and mortality related to infections, lowers the risk of chronic diseases, and supports neurodevelopment. It also has long-term protective effects for maternal health. However, exclusive breastfeeding rates are still below desired levels globally, ranging from 44-48%, and are 41% in Turkey. These low rates are associated with various factors, including maternal characteristics, birthing process, socioeconomic status, and access to health services.

Hormonal changes and sleep disturbances experienced during the postpartum period increase maternal anxiety, and breastfeeding difficulties are more common in primiparous mothers. Mothers are reported to require professional support in coping with problems and understanding infant behavior.

According to Bandura's Social Cognitive Theory, self-efficacy is an individual's belief in their capacity to successfully perform a specific task. Dennis's breastfeeding self-efficacy model shows that high self-efficacy is a determinant factor in initiating, continuing, and exclusively breastfeeding. Perceived insufficient milk supply is also a significant factor in early breastfeeding cessation. Problems such as pain, nipple trauma, and infant restlessness reinforce this perception. Low self-efficacy and perceived insufficient milk supply increase the need for formula supplementation. Kent et al. (2021) reported that 44% of mothers felt their milk supply was insufficient, leading 66% of them to provide formula. Therefore, WHO and UNICEF emphasize the importance of individual-needs-focused professional support for at-risk mothers.

Current breastfeeding education programs are reported to be insufficient in meeting the long-term needs of mothers, especially in the postpartum period, indicating a need for more comprehensive and holistic programs to increase breastfeeding self-efficacy. The literature suggests that while education increases self-efficacy and breastfeeding success, the sustainability of this effect needs to be strengthened. Digital platforms enhance the accessibility of breastfeeding counseling.

Yoga is a holistic practice based on breathing, stretching, and mindfulness, providing positive effects on stress, anxiety, and depression. Yoga practice during the prenatal and postnatal periods is reported to support physical and psychological well-being and reduce stress hormones. Findings also suggest that yoga practices in the postpartum period may have positive effects on milk production, oxytocin levels, and breastfeeding success.

Studies examining the relationship between yoga and breastfeeding in the national literature are limited. Arabacı (2024) demonstrated that yoga-breathing exercises had positive effects on breastfeeding success and self-efficacy. Boybay Koyuncu (2019) evaluated the effects of postpartum yoga on breastfeeding adequacy and maternal bonding. However, there is no study examining the effect of structured breastfeeding education based on the breastfeeding self-efficacy theory, integrated with breath-based yoga, on psychosocial outcomes such as anxiety and perceived insufficient milk supply.

Therefore, this randomized controlled trial aims to evaluate the effects of breath-based yoga supported breastfeeding education on anxiety, breastfeeding self-efficacy, and perceived insufficient milk supply in primiparous mothers. The intervention combines education based on the Breastfeeding Self-Efficacy Model with breath-based yoga practices, and its online delivery facilitates mothers' access to professional support. The study is expected to offer an innovative and holistic model for breastfeeding counseling and postpartum nursing care.

Methodology: This randomized controlled trial will be conducted to evaluate the effect of breath-based yoga supported breastfeeding education on anxiety, breastfeeding self-efficacy, and perceived insufficient milk supply in primiparous mothers during the postpartum period. The research will be carried out in Family Health Centers in the Sakarya province and will be reported according to the CONSORT 2025 guideline.

The study sample size was determined using the G*Power (v3.1) software for a three-group design. Based on the effect size ($Cohen's$ $f = 0.36$) obtained from a similar breastfeeding education study in the literature, the power analysis calculated that 26 participants per group would be sufficient, using parameters of $\alpha = 0.05$ and 1-$\beta = 0.80$. Considering a 15% increase for potential data losses, the final sample size is planned as a total of 90 participants, with 30 mothers in each group.

Primiparous mothers registered at the Family Health Centers, who are within 0-2 weeks postpartum and meet the inclusion criteria, will be enrolled. After informed consent and baseline assessments, mothers scoring below 13 points on the Edinburgh Postpartum Depression Scale will be included in the sample. The block randomization method will be preferred for assigning participants to the study and control groups. Following randomization, mothers will be assigned to Intervention Group I (breastfeeding education + yoga, n = 30), Intervention Group II (breastfeeding education only, n = 30), or the control group (n = 30). The randomization sequence will be generated by an independent statistician using a computer-based method and implemented via the opaque envelope method. Due to the nature of the intervention, participant blinding is not possible; analyses will be conducted by a blinded statistician.

Interventions and Timeline: The data collection tools for this study are the Introductory Information Form, BSES-SF, Perceived Insufficient Milk Supply Scale, STAI State-Trait Anxiety Inventory, and Edinburgh Postnatal Depression Scale (EPDS).

The interventions will be conducted online via Google Meet in small groups of 5, starting from the 2nd postpartum week (T1). The breastfeeding education program will consist of six synchronous sessions of 30-60 minutes each, held twice a week for three weeks. In the education + yoga group (Intervention I), breath-based yoga will be applied twice a week for 45-60 minutes for four weeks following the breastfeeding education. The control group will continue to receive routine Family Health Center services with no intervention. The same scales will be administered in all groups at T1 (2nd week), T2 (5th week), and T3 (9th week). The research will analyze changes over time and differences between groups to evaluate the effectiveness of the yoga-supported breastfeeding education.

Inclusion Criteria:

Inclusion Criteria for Intervention and Control Groups

• Primiparous mothers aged 19 years or older who delivered at term (37-42 weeks),
• Mothers who gave birth in a Baby-Friendly Hospital in Sakarya,
• Mothers who are open to communication and cooperation, voluntarily agree to participate in the study, and had a normal vaginal delivery,
• Mothers who agree to participate in the study during postpartum weeks 0-2 and who will be in postpartum weeks 2-10 during the intervention period,
• Mothers who breastfeed or practice mixed feeding,
• Mothers and infants who are in good health,
• Mothers with a Body Mass Index within the normal range,
• Mothers without sensory impairments such as hearing or vision problems,
• Mothers without a diagnosed psychiatric history,
• Mothers who can read and write in Turkish,
• Mothers who score below 13 on the Edinburgh Postpartum Depression Scale (EPDS) at the first assessment.

Exclusion Criteria for Intervention and Control Groups

• Infant loss,
• Mothers with visual, auditory, or cognitive impairments,
• Infants with physical disabilities or congenital anomalies,
• Mothers with any neurological, orthopedic, or chronic condition that may prevent participation in exercise,
• Mothers scoring 13 or above on the Edinburgh Postnatal Depression Scale (EPDS) at the first assessment,
• Mothers who practiced yoga or breathing exercises during pregnancy or postpartum will be excluded,
• Since brief educational sessions provided before discharge in Baby-Friendly Hospitals are routine in Turkey, they will not be considered exclusion criteria.
• However, mothers who received a structured breastfeeding education program during pregnancy or postpartum will be excluded from the study.

Withdrawal Criteria for Intervention and Control Groups

• Participants who request to withdraw from the study at any time,
• Participants who miss more than two yoga-breathing sessions, more than two breastfeeding education sessions, or who cannot be reached will be removed from the study.

Only individuals who self-identify as female are eligible to participate, as the study focuses on postpartum biological females.

Individual participant data will not be shared due to privacy and confidentiality considerations.

This study will use a single-blind design. While participants and intervention providers will not be blinded due to the nature of the education and yoga sessions, the outcomes assessor (statistician) will be blinded to group allocation during data analysis to reduce assessment bias.