Effect of Mindfulness Training on the Clinical Pregnancy Rate in Women Undergoing Frozen Embryo Transfer: Study Protocol for a Single-Center, Open-Label, Randomized Controlled Trial

Objective: To evaluate the effect of mindfulness training in addition to essential psychological counseling on the clinical pregnancy rate in women undergoing frozen embryo transfer (FET), and to explore the potential mediating role of neuropsychological improvements. Methods and Analysis: This study will be conducted as a single-center, parallel-group, open-label, exploratory randomized controlled trial. Eligible women aged 18– 45 years undergoing FET who present with psychological distress (mild to moderate anxiety symptoms, depressive symptoms, poor sleep quality, or psychosocial stress overload) will be recruited. Participants will be randomly assigned in a 1:1 ratio to either the Mindfulness Training Group (MTG), which delivers structured formal mindfulness practice, or the Essential Psychological Counseling Group (EPCG), which provides supportive psychoeducation and emotional guidance without mindfulness-based training. The primary endpoint will be the clinical pregnancy rate. Secondary endpoints include changes in anxiety symptoms, depressive symptom, sleep quality, and psychosocial stress; the live birth rate will be assessed exploratorily. Mediation analyses will be performed to assess whether neuropsychological improvements explain the relationship between mindfulness training and clinical pregnancy. A total of 434 participants will be enrolled, allowing for a 20% dropout rate. Trial Registration: This trial is registered with the Chinese Clinical Trial Registry (ChiCTR2600116827).