The purpose of this pilot study is to evaluate the feasibility, acceptability, and preliminary effects of an Acceptance and Commitment Therapy (ACT)-based psychosocial intervention for women who have experienced perinatal loss (miscarriage, stillbirth, or neonatal death). The intervention is a 4-week programme delivered in a mixed format: four in-person sessions (hospital setting, one-on-two with spouse/significant other) and two videoconferencing sessions (post-discharge, one-on-one), plus a 30-minute booster session one month after completion. Outcome assessments will occur at baseline (pre-intervention), immediately post-intervention, and three months post-intervention. Primary feasibility and acceptability metrics include recruitment, retention, session attendance, and participant-rated satisfaction. Preliminary effectiveness outcomes include perinatal grief, post-traumatic stress, depression, anxiety, psychological flexibility, and perceived social support. A qualitative component (semi-structured interviews) will explore participants' experiences and suggestions for refinement.

Background Perinatal loss, including miscarriage, stillbirth, and neonatal death, is a profound traumatic event affecting approximately 15-20% of pregnancies. Women who experience perinatal loss are at elevated risk for prolonged grief disorder, major depressive disorder, post-traumatic stress disorder, and anxiety disorders. Although maternal mental health has gained increasing attention in China, evidence-based, culturally adapted psychosocial interventions for perinatal loss remain scarce. Preliminary surveys by our research team indicate a strong need for grief support among bereaved women, yet healthcare providers (midwives and nurses) lack the knowledge and skills to deliver such support.

Acceptance and Commitment Therapy (ACT), a third-wave cognitive behavioural approach, has shown benefits for individuals experiencing grief and trauma by increasing psychological flexibility-an empirically supported process linked to improved mental health and adaptive coping. ACT targets six core processes: acceptance, cognitive defusion, contact with the present moment, self-as-context, values clarification, and committed action. However, prior trials in perinatal loss populations remain limited, and no culturally adapted ACT-based intervention has been evaluated in the Chinese context.

Intervention This study tests a 4-week ACT-based psychosocial intervention delivered across six sessions (45-60 minutes each), plus a 30-minute booster session one month after the final session. The intervention integrates four thematic components: (1) perinatal loss health education; (2) ACT-based grief and emotion management (acceptance, defusion, present-moment awareness, values, committed action); (3) postpartum rehabilitation mindfulness yoga; and (4) social support from significant others.

Delivery format is mixed to accommodate the inpatient-to-outpatient transition:

Sessions 1-4: In-person, hospital setting, one-on-two format (woman plus spouse/significant other), covering the inpatient period (admission, induction procedure, postoperative recovery).

Sessions 5-6: Remote via Tencent Meeting (videoconferencing), one-on-one format, covering the post-discharge physical and emotional recovery period.

Booster session: 30-minute remote session one month after session 6. Participants receive a workbook containing session summaries and homework assignments. QR codes in the workbook provide access to online instructional videos for home-based mindfulness meditation or mindfulness yoga practice.

Study Design This is a single-arm pilot interventional study (pre-experimental design). A waitlist control or parallel control group is not included in this pilot phase; findings will inform the design of a future large-scale randomised controlled trial.

Participants and Eligibility Women aged ≥18 years who have experienced perinatal loss (miscarriage, stillbirth, or early neonatal death) within the past 12 months are eligible. Exclusion criteria include current severe mental illness (e.g., schizophrenia, bipolar disorder acute episode), active suicidal ideation with plan or intent, and concurrent participation in other systematic psychotherapy. A target sample of approximately 30 participants is planned, consistent with recommendations for feasibility studies (10-40 participants per group).

Outcome Measures

Quantitative measures:

Perinatal grief: 15-item Perinatal Grief Scale (PGS-SF; Li et al., 2025) Post-traumatic stress: Impact of Event Scale-Revised (IES-R; Wu & Chan, 2004) Depression: Patient Health Questionnaire-9 (PHQ-9; Wang et al., 2014) Anxiety: Generalized Anxiety Disorder-7 (GAD-7; Zeng et al., 2013) Psychological flexibility: Psy-Flex-C (Li et al., 2024a) Perceived social support: Perceived Social Support Scale (PSSS; Zhao, 2022) Intervention satisfaction: Adapted Chinese Standardized Client Satisfaction Scale (C-SCS, 18 items, 5-point Likert; Liu & Chen, 2022)

Qualitative component:

Descriptive qualitative study using semi-structured interviews conducted within two weeks post-intervention with all pilot participants.

Interview duration: 20-30 minutes, audio-recorded (iFlytek SR701). Verbatim transcription within 48 hours with annotations for pauses, tone, and nonverbal cues.

Thematic analysis to identify themes related to intervention acceptability, facilitators, barriers, and suggestions for refinement.

Assessment Schedule Assessments occur at three time points: baseline (T0, pre-intervention), immediately post-intervention (T1), and three months post-intervention (T2). Satisfaction surveys are administered at T1. Qualitative interviews are conducted within two weeks post-intervention.

Data Management and Quality Control Quantitative data are collected via an online survey platform (Questionnaire Star, WJX.cn) under the guidance of a research assistant independent from intervention delivery. Data are exported in encrypted format and stored on a password-protected institutional server. Regular data audits are performed by the principal investigator. For qualitative data, two researchers independently code a subset of transcripts to ensure reliability; discrepancies are resolved through discussion.

Data Analysis Feasibility outcomes (recruitment rate, retention rate, session attendance, satisfaction scores) will be analysed using descriptive statistics. Preliminary efficacy will be explored using repeated measures ANOVA or mixed-effects models to examine changes in outcome measures across T0, T1, and T2. Effect sizes (Cohen's d) will be calculated to inform sample size estimation for a future full-scale randomised controlled trial. Qualitative data will be analysed using thematic analysis following Braun & Clarke's six-phase framework.

Hypotheses We hypothesise that the ACT-based psychosocial intervention will be feasible and acceptable to women with perinatal loss, as evidenced by recruitment rate ≥50%, retention rate ≥70%, session attendance ≥75%, and mean satisfaction scores ≥4 out of 5. We also hypothesise that participants will show improvements in perinatal grief, post-traumatic stress, depression, anxiety, psychological flexibility, and perceived social support from baseline to post-intervention and three-month follow-up, with small-to-moderate effect sizes.

Inclusion Criteria:

• Women aged ≥18 years
• Experienced perinatal loss (including miscarriage, stillbirth, or early neonatal death) within the past 12 months
• Spouse/partner willing to participate throughout the entire study
• Able to read and communicate in Chinese
• Willing and able to provide written informed consent

Exclusion Criteria:

• Current diagnosis of severe mental illness (e.g., schizophrenia, bipolar disorder acute episode, psychotic disorder)
• Active suicidal ideation with plan or intent, as assessed by clinical judgment or PHQ-9 item 9 score ≥1
• Concurrent participation in other systematic psychotherapy or psychosocial intervention
• Cognitive impairment that precludes understanding of the intervention content

Considering ethical reasons and participant privacy, we will not make individual participant data publicly available.