This single-center randomized controlled clinical trial will evaluate the effects of structured early postpartum mother-infant skin-to-skin contact, with or without maternal lavender aromatherapy, after elective cesarean section on maternal stress biomarkers and early breastfeeding outcomes. The study will enroll 150 term pregnant women scheduled for elective cesarean section under spinal anesthesia at Ataturk University Research Hospital. Participants will be randomized into three groups: routine postoperative care, structured skin-to-skin contact, and structured skin-to-skin contact combined with inhalational lavender aromatherapy. The primary outcome is the change in maternal salivary cortisol level from immediately after birth to 60 minutes postpartum. Secondary outcomes include maternal salivary IgA levels, state anxiety scores, postoperative pain and nausea, time to first analgesic requirement, early breastfeeding initiation and success, LATCH scores, neonatal axillary temperature, cumulative duration and continuity of skin-to-skin contact, maternal satisfaction, and the need for mother-infant separation within the first 2 hours postpartum.

Cesarean section rates are increasing worldwide, and optimizing maternal and neonatal outcomes in the early postpartum period has become a clinical priority. Elective cesarean delivery is associated with surgical and anesthetic stress, altered hypothalamic-pituitary-adrenal axis activation, and delayed mother-infant interaction, which may negatively affect bonding and breastfeeding. Early skin-to-skin contact between mother and newborn is an evidence-based physiological intervention that promotes thermal stability, attenuates stress responses, and supports breastfeeding, but its hormonal and biochemical mechanisms after elective cesarean section have not been fully elucidated. Lavender aromatherapy is a non-pharmacological method that has been reported to reduce perioperative anxiety and pain in cesarean mothers; however, its combined use with structured skin-to-skin contact in the early postpartum period has not been previously investigated in a randomized controlled design.

This prospective, randomized, controlled, three-arm interventional study will be conducted in the Obstetrics and Gynecology Clinic of Ataturk University Faculty of Medicine Research Hospital. A total of 150 volunteer pregnant women aged 18-40 years with term singleton pregnancies scheduled for elective cesarean section under spinal anesthesia and classified as ASA physical status I-II will be included. Participants will be randomized in equal numbers (n=50 per group) to: Group 1, routine postoperative care; Group 2, structured early postpartum mother-infant skin-to-skin contact; and Group 3, structured skin-to-skin contact plus maternal inhalational lavender aromatherapy. All interventions will be delivered by anesthesiology investigators trained in the study protocol. Salivary samples for cortisol and IgA will be collected immediately after birth (T0) and at 60 minutes postpartum (T1). State anxiety (STAIS-5), postoperative pain (VAS), nausea-vomiting, time to first analgesic requirement, breastfeeding initiation time, breastfeeding success within the first 60 and 120 minutes, LATCH scores, neonatal axillary temperature, cumulative duration and interruptions of skin-to-skin contact, the need for mother-infant separation, and maternal satisfaction at 120 minutes (T2) will be systematically recorded using predefined case report forms.

Routine intraoperative and postoperative monitoring and care will be maintained for all participants, and no additional invasive procedures or pharmacological agents beyond standard practice will be introduced. Statistical analyses will be performed using IBM SPSS Statistics v26.0. Continuous variables will be summarized as mean and standard deviation or median and interquartile range as appropriate, and categorical variables as counts and percentages. Between-group comparisons will use one-way ANOVA or Kruskal-Wallis tests for continuous variables and chi-square or Fisher's exact tests for categorical variables. Changes in cortisol over time will be analyzed with repeated-measures methods, and the relationship between cumulative skin-to-skin duration and cortisol change will be assessed using Pearson or Spearman correlation coefficients. All comparisons will be reported with 95 confidence intervals, with a two-sided p value less than 0.05 considered statistically significant.

Inclusion Criteria:

• Female participants aged 18 to 40 years
• Term singleton pregnancy (≥37 weeks of gestation)
• Scheduled for elective cesarean section
• ASA physical status I-II
• Planned spinal anesthesia
• Clinically stable mother and newborn immediately after birth
• Ability to initiate breastfeeding in the early postpartum period
• Provision of written informed consent

Exclusion Criteria:

• Emergency cesarean section
• General anesthesia or conversion from spinal to general anesthesia
• Need for neonatal resuscitation or severe neonatal compromise
• Maternal hemodynamic instability or massive hemorrhage
• Major fetal congenital anomalies
• Known allergy or intolerance to lavender
• Severe asthma or intolerance to strong odors
• Major psychiatric disorders
• Serious endocrine diseases affecting stress hormone regulation
• Clinical conditions that preclude breastfeeding
• Contraindications to spinal anesthesia
• Refusal to participate in the study

There is no current plan to share individual participant data (IPD) outside the study team due to institutional and national data protection regulations.

Open-label to participants and care providers; laboratory personnel and statistical analysis team will be blinded to group allocation when assessing biochemical and outcome data (outcomes assessor-masked).