Psychometric evaluation of the Birth Trauma Scale among Iranian women

Abstract

Birth-related psychological trauma refers to mental health disorders resulting from negative experiences during labor and delivery, and it can negatively affect the mother's mental health, family relationships, and even child development.

Objective

This study assessed the psychometric properties of the Birth Trauma Scale among Iranian women.

Methods

This study involved 311 women, 4 to 8 weeks postpartum, selected through cluster random sampling from August 2024 to December 2025. The validity of the Birth Trauma Scale was assessed in five stages: content validity and face validity (both quantitatively and qualitatively), structural validity using exploratory factor analysis and confirmatory factor analysis, and reliability determined through internal consistency and test-retest reliability.

Results

In this study, the Content Validity Index and Content Validity Ratio of the Birth Trauma Scale were 0.98 and 0.97, respectively. The tool's four-factor structure in the exploratory factor analysis explained 59% of the variance. The model's fit indices in the confirmatory factor analysis supported its validity (Root Mean Square Error of Approximation = 0.078, Tucker–Lewis Index = 0.98, Comparative Fit Index = 0.98, normed chi-square= 3.9). Furthermore, Cronbach's alpha was 0.91, and the intra-class correlation coefficient with a 95% confidence interval was 0.88 (0.75 to 0.95).

Conclusions

The Persian version of the Birth Trauma Scale is a valid and reliable instrument for evaluating psychological birth trauma in the Iranian population.

Code number

IR.TBZMED.REC.1402.945.

What is already known.

• •Reliable and valid instruments are essential for accurate assessment of “Birth Trauma Scale” in midwifery research.
• •Existing tools have shown limitations in cultural adaptation and psychometric performance.

What this paper adds.

• •This study provides a comprehensive psychometric evaluation of the “Birth Trauma Scale” in a midwifery scale.
• •The findings support the validity and reliability of the instrument for use in Iranian setting.

1. Introduction

Childbirth is a significant life event and one of a woman's most unique and meaningful experiences (Vedeler et al., 2022). It involves not only physical changes but also significant psychological shifts. During pregnancy, women encounter substantial challenges, including physical transformations, psychological stress, role adjustments, and changes in family dynamics (Fenech and Thomson, 2014). Additionally, childbirth is a complex and multidimensional process that includes physical, psychological, emotional, social, and cultural components (Khaled et al., 2020). The dynamic nature of childbirth is marked by interactions between psychological and physiological mental processes (McKelvin et al., 2021).

Psychological birth trauma refers to a range of psychological distress and negative emotional responses experienced by women during childbirth and in response to stressful events. This phenomenon is subjective and influenced by various factors, including individual perceptions of the birth experience, interactions with healthcare providers, and cultural and social expectations (Wu et al., 2025). In other words, psychological birth trauma, also known as traumatic birth, is defined as emotional disturbances and mental health challenges arising from negative or distressing experiences during labor. These experiences may include severe anxiety, psychological distress, and discomfort resulting from adverse events, leading the mother to suffer from a series of psychological pains and adverse reactions, such as intense fear, a sense of helplessness, loss of autonomy, and overwhelming emotional anxiety (Freestun et al., 2025).

Psychological birth trauma and childbirth-related post-traumatic stress disorder are closely related but conceptually distinct constructs. Psychological birth trauma primarily refers to a woman’s subjective perception and emotional and psychological response to childbirth as a traumatic or highly distressing experience, which may involve fear, helplessness, loss of control, perceived lack of support, or other overwhelming reactions. In contrast, childbirth-related post-traumatic stress disorder represents a clinical pattern of post-traumatic stress symptoms that develops following a traumatic childbirth experience and is characterised by specific symptom clusters, including re-experiencing, avoidance, negative alterations in cognition and mood, and hyperarousal. Thus, perceiving childbirth as traumatic does not necessarily indicate that a woman meets the diagnostic criteria for post-traumatic stress disorder. The diathesis–stress model proposed by Ayers et al. (2016) provides an important theoretical framework for understanding the development of post-traumatic stress following childbirth. Within this framework, childbirth-related post-traumatic stress results from the interaction between pre-existing vulnerability factors, characteristics of the birth experience, and postpartum maintaining factors. Pre-existing psychological difficulties and antenatal fear or distress may increase vulnerability, while factors occurring during childbirth, including a negative subjective birth experience, perceived lack of support, and obstetric complications or interventions, may contribute to the development of post-traumatic stress symptoms. Postpartum psychological and social factors may subsequently influence their persistence. This framework is particularly relevant to psychological birth trauma because it highlights the importance of women's subjective appraisal of childbirth alongside objective obstetric events. More recent evidence has similarly conceptualised childbirth-related post-traumatic stress disorder as a multifactorial condition involving individual vulnerability, childbirth-related experiences, and postpartum factors, while emphasising the importance of appropriate identification, prevention, and treatment (Horsch et al., 2024).

The worldwide prevalence of psychological birth trauma symptoms in women is approximately 19% (Xu et al., 2022). Research shows that about one-third of women describe their childbirth experience as traumatic (Slade et al., 2022). Primiparous women, who have not gone through childbirth before, are often overwhelmed by intense fear of pain and uncertainty during labor, which makes them more vulnerable to symptoms of psychological birth trauma (Green et al., 2022). Other studies suggest even higher rates, with up to 45% (Alcorn et al., 2010), 55% (Halperin et al., 2015), or >60% of women reporting such experiences (Soet et al., 2003; Türkmen et al., 2020, 2021). Across different studies, the prevalence of Psychological birth trauma globally ranges from 20% to 68.6% (Qin et al., 2025; Sun et al., 2023). In a survey by McKelvin et al. (2021) in the United Kingdom, 34% of women reported experiencing psychological trauma related to childbirth (McKelvin et al., 2021). Another study in Iran found a prevalence rate of 48.3% for psychological birth trauma (Abdollahpour, 2017).

Experiencing trauma during childbirth can adversely affect a mother's psychological health and her adjustment during the postpartum period (Freestun et al., 2025). A sudden traumatic event can disrupt a person's sense of control and shatter their core beliefs and perceptions about the world and those around them. Additionally, birth-related trauma, regardless of how stressful the situation appears, can negatively impact the mental health of the mother, infant, and partner during the postpartum period (Azizi et al., 2010). Women affected by trauma may experience decreased self-confidence, confusion, anxiety, and challenges in performing daily tasks (Sangestani., 2013). Poor postpartum mental health can change a woman's self-perception and strain family relationships (Anderson., 2020; Tietz., 2014). Qualitative research indicates that psychological trauma can harm marital relationships and the bond between mother and infant (Shaw et al., 2009), and it may also negatively influence the child's emotional, social, and cognitive development (Parfitt and Ayers, 2009).

Various factors influencing psychological birth trauma have been identified, mainly including three aspects: social factors, family environment factors, and individual characteristics of the birthing woman (Xu et al., 2022; Ma et al., 2023). Adequate social and family support—particularly spousal support during childbirth—can significantly lower the risk of psychological birth trauma. In contrast, labor pain, as well as depression and anxiety during pregnancy, can markedly increase the risk of psychological birth trauma (Türkmen et al., 2021). Pain during childbirth is recognized as a key risk factor for psychological trauma in birthing women (Xu et al., 2022). Physical injuries resulting from childbirth, such as perineal tears, may cause unbearable pain that persists from the labor process into the postpartum recovery period and severely impacts women's mental health (Ju et al., 2024; Opondo et al., 2023). Moreover, pain can provoke intense fear and anxiety in primiparous women, which may intensify psychological distress and raise the likelihood of experiencing psychological birth trauma. However, differences in research design, sample characteristics, and data analysis methods have led to variations in the reported magnitude and strength of associations between specific influencing factors (Wang et al., 2025).

In Iran, several studies have investigated post-traumatic stress symptoms following childbirth using established instruments, including Posttraumatic Stress Disorder Symptom Scale–Interview Version and the Postpartum post-traumatic stress disorder Questionnaire (Abdollahpour et al., 2017; Abedian et al., 2013; Mahmoodi et al., 2016; Modarres et al., 2010; Shaban et al., 2013; Vizeh et al., 2012). In addition, the City Birth Trauma Scale, developed by Ayers et al. (2018), is an established birth-specific instrument designed to assess childbirth-related post-traumatic stress disorder according to DSM-5 criteria and has subsequently been translated and psychometrically evaluated across different linguistic and cultural contexts. The City BiTS therefore represents an important instrument when the primary purpose is the assessment of childbirth-related post-traumatic stress disorder. However, psychological birth trauma and childbirth-related post-traumatic stress disorder are related but not interchangeable constructs. A woman may perceive childbirth as psychologically traumatic and experience substantial birth-related distress without necessarily meeting diagnostic criteria for post-traumatic stress disorder. Consequently, instruments structured primarily around post-traumatic stress disorder symptomatology may not fully characterize broader non-diagnostic dimensions of the subjective traumatic birth experience, including perceived neglect and loss of control.

The Birth Trauma Scale, developed by Zhang et al. (2023), was specifically designed to assess this broader construct of psychological birth trauma from a childbirth-specific and multidimensional perspective. The 15-item Birth Trauma Scale comprises four dimensions: Being Neglected, Out of Control, Physiological-Emotional Response, and Cognitive-Behavioral Response. Its development incorporated qualitative exploration of women's traumatic childbirth experiences, expert consultation, and psychometric evaluation, allowing assessment of interpersonal and experiential dimensions of childbirth alongside women's physiological, emotional, cognitive, and behavioral responses (Zhang et al., 2023). Accordingly, the Birth Trauma Scale is not intended to replace established post-traumatic stress disorder -specific instruments such as the City Birth Trauma Scale; rather, it may provide complementary information by assessing dimensions of psychological birth trauma that extend beyond the diagnostic symptom profile of childbirth-related post-traumatic stress disorder. This broader construct coverage constituted an important rationale for selecting the Birth Trauma Scale for translation and psychometric evaluation in the present study.

Importantly, the experience and perception of childbirth are shaped not only by obstetric events but also by women's interactions with healthcare providers, perceived support and respect, involvement in decision-making, autonomy, expectations of maternity care, and broader social and cultural norms. These factors may vary across healthcare systems and cultural contexts and may influence how women perceive and report childbirth as traumatic. In the Iranian context, differences in maternity-care practices, the organization of childbirth services, women's involvement in childbirth-related decisions, and expectations regarding professional and social support may affect the manifestation and interpretation of psychological birth trauma. Therefore, an instrument developed and validated in another cultural and healthcare context cannot be assumed to have equivalent content relevance, factor structure, or measurement properties among Iranian women without formal translation, cultural adaptation, and psychometric evaluation.

Although the Birth Trauma Scale was specifically developed to assess psychological birth trauma, its psychometric properties had not been established among Iranian postpartum women. Translating and culturally adapting the Birth Trauma Scale was therefore necessary not merely to make the instrument linguistically accessible, but also to determine whether its items, conceptual domains, and underlying structure were culturally relevant and psychometrically appropriate for Iranian women. Accordingly, this study aimed to translate and culturally adapt the Birth Trauma Scale into Persian and to evaluate its psychometric properties among Iranian postpartum women. Specifically, we assessed its content validity, face validity, structural validity, hypothesis testing for construct validity, internal consistency, and test–retest reliability.

2. Methods

2.1. Aim

The current study aimed to assess the psychometric properties of the Birth Trauma Scale in an Iranian population.

2.2. Study design

The present psychometric evaluation was conducted as part of a previously published protocol for an explanatory sequential mixed-method study on psychological birth trauma and its related factors among Iranian women (Ranjbar et al., 2025). This methodological study aimed to translate, culturally adapt, and evaluate the psychometric properties of the Persian version of the Birth Trauma Scale among Iranian postpartum women. The translation, cultural adaptation, and psychometric evaluation procedures were guided by the Consensus-based Standards for the Selection of Health Measurement Instruments methodology and relevant recommendations for cross-cultural adaptation of self-report measures. The study included forward translation, back-translation, expert review and cultural adaptation, qualitative and quantitative assessment of face and content validity, assessment of structural validity using exploratory and confirmatory factor analyses, hypothesis testing for construct validity and evaluation of reliability through internal consistency and test–retest reliability. The overall process of translation, cultural adaptation, and psychometric evaluation of the Persian Birth Trauma Scale is illustrated in Fig. 1

Fig. 1.

Overall process of translation, cultural adaptation, and psychometric validation of the Persian Birth Trauma Scale (BTS). Exploratory factor analysis (n = 155), Confirmatory factor analysis (n = 156).

2.3. Study participants

The study involved 311 women who were 4 to 8 weeks postpartum and had visited health centers in Tabriz, Iran.

2.4. Eligibility criteria

Inclusion criteria consisted of women who had a vaginal birth and were 4 to 8 weeks postpartum.

Exclusion criteria included:

• •Postpartum complications (such as bleeding, infection, breastfeeding problems, neonatal hospitalization);
• •History of stillbirth or child loss;
• •Self-reported or medically documented mental illness;
• •Experience of a traumatic life event in the past three months (such as the death of a loved one, divorce, etc.);
• •History of repeated cesarean section;
• •Presence of chronic or systemic diseases or pregnancy-related exacerbated disorders;
• •High-risk pregnancies.

3. Sampling

3.1. Sample size

According to factor analysis guidelines, 5 to 10 samples are needed per item of the scale (Nunnally and Bernstein, 2010). Given that the Birth Trauma Scale includes 15 items, a minimum of 150 participants was required. However, considering the cluster sampling method and applying a design effect of 2, the sample size was increased to 300. Ultimately, 311 participants were included in the analysis. For the assessment of structural validity, the total sample (n = 311) divided randomly into two independent subsamples, with 155 participants included in the exploratory factor analysis and 156 participants included in the confirmatory factor analysis.

3.2. Recruitment

A multistage cluster sampling method with probability proportional to size was used. After obtaining ethical approval and the necessary permissions from the provincial and local health authorities, 61 of the 92 health centers in Tabriz (approximately two-thirds of all centers) were randomly selected. All health centers covered by Tabriz University of Medical Sciences were assigned numerical codes, and their order was randomly generated using the Random Sequence Generator at Random.org. The required centers were then selected according to this random sequence. For each selected health center, a list of women who were 4–8 weeks postpartum was retrieved from the SIB health information system. The number of women to be recruited from each center was determined using probability proportional to size, based on the number of potentially eligible postpartum women registered at that center. Women were then randomly selected from the corresponding center lists.

The selected women were initially contacted by telephone, informed about the study objectives and procedures, and assessed according to the predefined inclusion and exclusion criteria. Eligible women were invited to participate voluntarily and were offered a scheduled appointment at the health center. Women who attended in person provided written informed consent before completing the study questionnaires in a quiet and private setting. Participants were assured that their responses would remain anonymous and confidential. In-person attendance at the health center was not required for participation. Women who were unable to attend could complete the study materials remotely. The informed consent form and questionnaire were provided electronically, and participants were required to complete and sign the informed consent form before participating. For women who were unable to complete the questionnaire independently because of time constraints or other practical difficulties, the questionnaire items were administered by telephone by the researcher after the electronically provided informed consent form had been signed. These alternative modes of participation were available to reduce practical barriers associated with participation during the early postpartum period.

Based on records from the Integrated Health System (SIB), 548 women were initially identified as potentially eligible across the 61 selected health centers and were approached for telephone screening and follow-up. Of these, 140 either could not be reached despite telephone contact and follow-up or were found during screening not to meet the eligibility criteria, including cases involving stillbirth or discrepancies in the delivery information recorded in the system. Following screening, 408 women were confirmed as eligible. Among these women, 97 either declined participation or initially agreed to participate but did not complete the participation process. Ultimately, 311 women participated in the study, corresponding to a participation rate of 76.0% among confirmed eligible women.

3.3. Instruments

3.3.1. Demographic and obstetrics data questionnaire

The socio-demographic characteristics questionnaire included questions about age, whether the monthly income was sufficient for living expenses, the mother's and her spouse's education levels, and occupations. The obstetric questionnaire asked about gestational age at delivery, number of pregnancies, number of deliveries, number of living children, and miscarriage history. Content and face validity methods were used to evaluate the questionnaire's validity. It was distributed to nursing, midwifery, and medical school faculty members, and after receiving their feedback, the tools were revised accordingly.

3.3.2. Birth Trauma Scale

Zhang et al. (2023) developed the Birth Trauma Scale to assess psychological birth trauma. The scale consists of 15 items across four subdomains: Being Neglected (4 items), Out of Control (3 items), Physiological Emotional Response (4 items), and Cognitive Behavioral Response (4 items). Participants respond to each item using a five-point Likert scale ranging from strongly disagree (1 point) to strongly agree (5 points). The total score ranges from 15 to 75, with higher scores indicating greater psychological birth trauma.

The original Birth Trauma Scale demonstrated satisfactory psychometric properties in a sample of 712 postpartum women in China. Content validity was supported by a scale-level content validity index of 0.942 and item-level content validity indices ranging from 0.870 to 1.000. Exploratory factor analysis supported a four-factor structure comprising 15 items, which explained 66.724% of the total variance, and confirmatory factor analysis demonstrated an acceptable model fit. Regarding reliability, Cronbach’s alpha was 0.874 for the total scale and ranged from 0.804 to 0.904 across the four dimensions. Split-half reliability was 0.774 for the total scale and ranged from 0.763 to 0.882 across the dimensions (Zhang et al., 2023).

3.3.3. Measures used for hypothesis testing of construct validity

Childbirth experience was assessed using the Childbirth Experience Questionnaire 2.0 (CEQ2.0), which assesses Own Capacity, Professional Support, Perceived Safety, and Participation. Higher mean scores indicate a more positive childbirth experience. The original CEQ demonstrated satisfactory construct and discriminant validity, with a four-factor structure accounting for approximately 54% of the total variance. Cronbach's alpha coefficients for the four domains ranged from 0.62 to 0.88 (Dencker et al., 2010). The Persian version demonstrated satisfactory content and construct validity, with content validity index values ranging from 0.83 to 1.00 and content validity ratio values ranging from 0.80 to 1.00. Confirmatory factor analysis supported its four-factor structure (RMSEA = 0.07, TLI = 0.97, CFI > 0.91). The total scale showed high internal consistency (Cronbach's α = 0.93) and test–retest reliability (ICC > 0.90) (Ghanbari-Homayi et al., 2019). In the present study, Cronbach's α was 0.90.

Postpartum-specific anxiety was assessed using the 16-item Postpartum Specific Anxiety Scale–Research Short Form (PSAS-RSF). Total scores range from 16 to 64, with higher scores indicating greater postpartum-specific anxiety. The original PSAS-RSF demonstrated good construct validity, with confirmatory factor analysis supporting its four-factor structure (CFI = 0.98, TLI = 0.97, RMSEA = 0.04, and SRMR = 0.06). The overall scale also demonstrated good internal consistency (McDonald’s ω = 0.88) (Davies et al., 2021). The Persian version demonstrated satisfactory face, content, and construct validity. The content validity index and content validity ratio were 0.91 and 0.97, respectively. Exploratory factor analysis yielded a four-factor structure, and confirmatory factor analysis demonstrated acceptable model fit (χ²/df = 1.521, RMSEA = 0.054, CFI = 0.920, SRMR = 0.060, and TLI = 0.898). The scale also demonstrated acceptable internal consistency (Cronbach's α = 0.72) and excellent test–retest reliability (ICC = 0.97, 95% CI: 0.93–0.98) (Mashayekh-Amiri et al., 2023). In the present study, Cronbach's α was 0.87.

Postpartum depressive symptoms were assessed using the 10-item Edinburgh Postnatal Depression Scale (EPDS). Total scores range from 0 to 30, with higher scores indicating greater depressive symptom severity. In the original validation study, the EPDS demonstrated satisfactory validity, with a sensitivity of 86%, specificity of 78%, and positive predictive value of 73%. It also demonstrated good reliability, with a split-half reliability coefficient of 0.88 and a standardized alpha coefficient of 0.87 (Cox et al., 1987). The Iranian version demonstrated satisfactory construct validity, including convergent and known-groups validity, and a three-factor structure accounting for 58% of the total variance. Internal consistency was satisfactory (Cronbach's α = 0.77–0.86), and test–retest reliability was acceptable (ICC = 0.80) (Montazeri et al., 2007). In the present study, Cronbach's α was 0.87.

Postpartum post-traumatic stress disorder symptoms were assessed using the 17-item Post-traumatic Stress Disorder Symptom Scale (PSS), which comprises three symptom domains: re-experiencing (4 items), avoidance (7 items), and arousal (6 items). Total scores range from 0 to 51, with higher scores indicating greater post-traumatic stress disorder symptom severity. In the original validation study, the self-report version of the PSS (PSS-SR) demonstrated good internal consistency (Cronbach's α = 0.91) and acceptable one-month test–retest reliability (r = 0.74), as well as satisfactory concurrent and convergent validity (Foa et al., 1993). In an Iranian sample, the PSS demonstrated good internal consistency (Cronbach's α = 0.88) and concurrent validity with psychiatric interview (r = 0.79, p < 0.001). Test–retest reliability also showed complete diagnostic agreement (κ = 1.00) (Mirzamani et al., 2006). In the present study, Cronbach's α was 0.91.

3.3.4. Translation and cultural adaptation process

Permission to translate and culturally adapt the Birth Trauma Scale was first obtained from the original developers (Zhang et al., 2023). The original English version was translated into Persian using a forward–backward translation approach. For the forward translation, two independent translators who were fluent in English, native Persian speakers, and familiar with psychological birth trauma independently translated the questionnaire into Persian. The two translations were then compared, and discrepancies were discussed and resolved by consensus to develop a preliminary Persian version.

The preliminary Persian version was subsequently back-translated into English by an English translator who was fluent in Persian. The back-translated version was compared with the original English version to identify discrepancies in meaning and wording. Where discrepancies were identified, the Persian version was reviewed and revised by referring to the original English version. This process was used to preserve the conceptual and semantic meaning of the original instrument while ensuring that the wording was clear and appropriate for Persian-speaking women (Kalfoss., 2019)

To further ensure equivalence between the Persian and original versions, the translated items were evaluated at the conceptual and semantic levels. Conceptual equivalence was considered by examining whether each Persian item represented the same underlying concept and dimension of psychological birth trauma as the corresponding item in the original Birth Trauma Scale. Semantic equivalence was assessed through comparison of the forward-translated, back-translated, and original English versions, with discrepancies in meaning and wording discussed and resolved through consensus.

The preliminary Persian version was then reviewed by a panel of 10 experts with doctoral degrees in midwifery or reproductive health. Their areas of expertise included maternal health, reproductive health, and midwifery, and their professional experience ranged from 10 to 30 years. Experts were selected based on having a relevant doctoral degree, research experience in maternal and reproductive health, and clinical experience in maternal or reproductive healthcare. The experts reviewed the translated items for grammar, wording, item placement, scaling, and appropriateness within the Iranian cultural and healthcare context. Cultural equivalence was evaluated by considering the appropriateness, relevance, and comprehensibility of each item within the Iranian cultural and maternity-care context. Their feedback was considered in revising the Persian version to improve its clarity and cultural appropriateness. No substantive changes to the underlying concepts or dimensional structure of the original Birth Trauma Scale were required during the translation and cultural adaptation process.

Both the original English and final Persian versions of the scale are provided in Appendix 1.

3.3.5. Face validity

Both qualitative and quantitative methods were used to assess face validity. In the qualitative approach, the perspective of the target population was considered. To gather opinions from the target group, interviews were conducted with 10 postpartum women to identify difficulties in understanding phrases and words, the relevance of items, and potential ambiguities in language. Based on their feedback, revisions were made to improve grammar and ensure the wording was appropriate and clear within Iranian society. Quantitative face validity was measured using the Item Impact Method. To determine the importance of each item, a 5-point Likert scale was employed: Completely Important (score 5), Important (score 4), Moderately Important (score 3), Slightly Important (score 2), and Not at All (score 1). The questionnaire was then distributed to 10 target group members, and face validity was calculated using the Impact Score formula (Frequency (%) × Importance). In this formula, Frequency (%) refers to the percentage of women who rated the item as 4 or 5, and Importance is the average score assigned by respondents to that item. An Impact Score above 1.5 is considered acceptable (Seyf., 2016).

3.3.6. Content validity

Content validity was assessed using both qualitative and quantitative methods. The same panel of 10 experts who participated in the cultural adaptation process was involved in the content validity assessment. The panel consisted of experts with doctoral degrees and expertise in midwifery or reproductive health, with 10–30 years of professional experience. Experts were selected based on holding a relevant doctoral degree, having research experience in maternal and reproductive health, and having clinical experience in the field. For the qualitative assessment, the experts evaluated the items with regard to grammar, wording, item placement, scaling, and their appropriateness and comprehensibility in the Iranian context. Based on their feedback, necessary modifications were made to the items.

For the quantitative assessment, a checklist comprising two sections was provided to each expert. The first section, used to calculate the Content Validity Index, asked the experts to rate the simplicity, relevance, and clarity of each item on a 4-point Likert scale. The second section, used to calculate the Content Validity Ratio, assessed the necessity of each item on a 3-point Likert scale ranging from "Not necessary" to "Essential." Items with a Content Validity Ratio above 0.62 and a Content Validity Index above 0.79 were considered to have acceptable content validity (Hajizadeh et al., 2011).

3.3.7. Structural validity

Structural validity refers to how well a measurement aligns with the theoretical concepts it aims to represent. In other words, it assesses whether a scale's items support the theoretical and operational definitions of the concept. Structural validity always focuses on the question: "What exactly does the scale measure?"(Harerimana and Mtshali, 2020). Exploratory Factor Analysis and Confirmatory Factor Analysis methods were used to establish structural validity.

3.4. Exploratory factor analysis

Exploratory factor analysis was conducted using the Kaiser-Meyer-Olkin measure and Bartlett's test of sphericity to assess the suitability of the data for factor analysis, applying principal component analysis with Promax rotation (Nia et al., 2014). An oblique Promax rotation was applied because correlations among the underlying factors were theoretically expected. The coefficients reported in the exploratory factor analysis table represent pattern coefficients from the Promax-rotated solution. The number of factors retained was determined using multiple criteria, including eigenvalues greater than 1, visual inspection of the scree plot, parallel analysis, and theoretical interpretability of the resulting factor structure in relation to the conceptual dimensions of the original Birth Trauma Scale.

Factor loadings above 0.30 were considered significant. According to Kaiser’s criterion, Kaiser-Meyer-Olkin values >0.50 were considered acceptable, with values between 0.50 and 0.70 classified as mediocre, 0.70–0.80 as good, 0.80–0.90 as great, and >0.90 as superb (Nia et al., 2014). Bartlett’s test of sphericity was considered statistically significant at p < 0.05.

3.4.1. Confirmatory factor analysis

In Confirmatory factor analysis, model fit was evaluated using several indices: Root Mean Square Error of Approximation <0.08, Comparative Fit Index equal to or greater than 0.90, Tucker–Lewis Index equal to or greater than 0.90, and normed chi-square <5 (Kline, 2023; Schreiber et al., 2006). The significance of model parameter estimates and the correlations among factors were also assessed (Tinsley and Brown, 2000).

3.5. Hypothesis testing for construct validity

Hypothesis testing for construct validity was performed by examining the relationships between total Birth Trauma Scale scores and theoretically related construct, including childbirth experience, postpartum post-traumatic stress symptoms, postpartum depression, and postpartum-specific anxiety. Based on the conceptual framework of psychological birth trauma, higher Birth Trauma Scale scores were hypothesized to be associated with more severe postpartum post-traumatic stress disorder, depressive, and anxiety symptoms and with negative childbirth experiences. Pearson's or Spearman's correlation coefficients were calculated as appropriate according to the distribution and measurement characteristics of the variables.

3.6. Reliability

Both stability and internal consistency were assessed to determine the reliability of the questionnaire. Stability was evaluated using test–retest reliability. The questionnaire was completed twice by 20 randomly selected mothers with a two-week interval. The Intraclass Correlation Coefficient and its 95% confidence interval were calculated for each subscale and the total score to evaluate stability. Internal consistency reliability was assessed using Cronbach’s alpha and McDonald’s omega for the total scale and its four subscales. A coefficient above 0.70 was considered acceptable (Hajizadeh et al., 2011).

3.7. Statistical analysis

Data were analyzed using the Statistical Package for the Social Sciences, version 26. Descriptive statistics, including mean (standard deviation) for quantitative variables and frequency (percentage) for qualitative variables, were used to describe sociodemographic and obstetric characteristics and other study variables. Content validity was assessed by calculating the Content Validity Ratio and Content Validity Index; face validity was evaluated using the Impact Score; structural validity was examined using exploratory factor analysis and confirmatory factor analysis; and reliability was assessed using Cronbach's alpha, McDonald's omega, and the intra-class correlation coefficient. Hypothesis testing for construct validity was performed by examining the correlations between total Birth Trauma Scale scores and theoretically related measures, including childbirth experience, postpartum-specific anxiety, postpartum depression, and postpartum post-traumatic stress disorder. Pearson's correlation coefficient was used to examine associations with childbirth experience and postpartum-specific anxiety, whereas Spearman's rank correlation coefficient was used for postpartum depression and postpartum post-traumatic stress disorder because these variables were not normally distributed. A two-sided p-value < 0.05 was considered statistically significant.

3.8. Ethical considerations

This study was approved by the Ethics Committee of Tabriz University of Medical Sciences (code number: IR.TBZMED.REC.1402.945). Professor Zeng Tieying emailed permission to use the Birth Trauma Scale before conducting the study. All participants provided written informed consent. They were assured that their information and identities would be kept confidential and that they could withdraw from the study anytime.

4. Results

Of the 408 women confirmed as eligible following telephone screening, 311 participated in the study, corresponding to a participation rate of 76.0%. The participants were 4–8 weeks postpartum and were recruited from the 61 selected health centers in Tabriz between August 2024 and December 2025. The mean (standard deviation) age of the participants was 29.73 (6.81) years, and the mean (standard deviation) gestational age at delivery was 38.34 (1.93) weeks. Approximately 60% of the participants had a diploma-level education or higher, and >78% had a history of one or two deliveries (Table 1).

Table 1.

Characteristics of the study participants (n = 311).

Characteristics	Mean (SD)
Age (Year)	29.7 (6.8)
Body Mass Index (Kg/m2)	25.1 (4.5)
Gestational age (Week)	38.3 (1.9)
	N (%)
Income
Not at all sufficient	50 (16.1)
Relatively sufficient	200 (64.3)
Completely sufficient	61 (19.6)
Educational level
Illiterate/ Primary school	34 (10.9)
Secondary school	53 (17.0)
High school	36 (11.6)
Diploma	115 (37.0)
University	73 (23.5)
Occupation
Housewife	274 (88.1)
Employee	37 (11.9)
Gravidity
One	114 (36.7)
Two	82 (26.4)
Three	70 (22.5)
Four and more	45 (14.5)
Birth agent
Gynecologist	118 (37.9)
Midwife	125 (40.2)
Student	68 (21.9)
Mode of Vaginal Delivery
With episiotomy	171 (55.0)
With a tear	90 (28.9)
Without episiotomy and tear	50 (16.1)
Hospital
Government	83(26.7)
Private	110(35.4)
Organizational	118(37.9)

SD: Standard Deviation; kg/m²: kilograms per square metre.

4.1. Face and content validity

In the qualitative assessment of face validity, all items were described as relevant, unambiguous, and understandable in terms of difficulty. In the quantitative evaluation with the Impact Score, all items scored at least 1.5. Additionally, in the content validity evaluation, all items achieved acceptable content validity index and Content Validity Ratio values. The content validity index and Content Validity Ratio for the entire instrument were 0.98 and 0.97, respectively.

4.2. Reliability

The total Birth Trauma Scale demonstrated excellent internal consistency (Cronbach’s α = 0.91; McDonald’s ω = 0.93). Test–retest reliability of the total scale was also satisfactory (ICC = 0.88, 95% CI: 0.75–0.95). Overall, the alpha and omega coefficients provided support for the internal consistency reliability of the scale and its subscales, although McDonald’s ω for the Out of Control subscale was comparatively lower (ω = 0.67).

4.3. Structural validity

Structural validity was evaluated using exploratory factor analysis and confirmatory factor analysis. A total of 311 women, 4–8 weeks postpartum, were recruited for the study. For the assessment of structural validity, the total sample was divided randomly into two independent subsamples. Exploratory factor analysis was conducted in a subsample of 155 participants, whereas confirmatory factor analysis was conducted in the remaining 156 participants. The Kaiser–Meyer–Olkin value was 0.64, indicating mediocre but acceptable sampling adequacy according to Kaiser’s criterion. Bartlett’s test of sphericity was statistically significant, χ²(105) = 719.80, p < 0.001, supporting the suitability of the correlation matrix for factor analysis. The number of factors to be retained was evaluated using multiple criteria, including eigenvalues greater than 1, visual inspection of the scree plot, parallel analysis, and theoretical interpretability. The four-factor solution was also theoretically interpretable and corresponded to the four conceptual dimensions of the original Birth Trauma Scale.

The four-factor structure in the exploratory factor analysis process accounted for 59% of the total variance. The first factor, "Being neglected," included four items and explained 17% of the total variance. The second factor, "Out of control," included three items and explained 12% of the variance. The third factor, "Physiological emotional response," included four items and explained 20% of the variance. Finally, the fourth factor, related to "Cognitive behavioral response," included four items and explained 10% of the total variance (Table 2).

Table 2.

Facture structure of the Birth Trauma Scale.

Scale item	Factor 1	Factor 2	Factor 3	Factor 4
Factor 1: Being Neglected
Q1. I felt like no one could help me during childbirth.	0.43
Q2. I felt like no one cared about me during childbirth.	0.92
Q3. I felt like no one understood my feeling during childbirth.	1.01
Q4. I felt like no one responded to my request during childbirth.	0.68
Factor 2: Out of control
Q5. I felt like I can't have a baby successfully during childbirth.		0.29
Q6. I can't control my emotions during childbirth.		1.07
Q7. I cannot control my behavior during childbirth.		0.83
Factor 3: Physiological emotional response
Q8. I get short of breath when I think of giving birth.			0.80
Q9. I sweat when I think of giving birth.			0.83
Q10. I get depressed when I think of giving birth.			0.91
Q11. I get nervous when I think of giving birth.			0.88
Factor 4: Cognitive behavioral response
Q12. My labor pains came from the baby.				0.89
Q13. My labor pains came from the medical staff.				0.59
Q14. This birth experience alienated me from my husband.				0.57
Q15. This birth experience made me refuse to breastfeed.				0.97
% Variance Explained	17	12	20	10
Total score	59
Cronbach’s alpha	0.794	0.741	0.940	0.790
Total score	0.910
McDonald’s ω	0.86	0.67	0.93	0.74
Total score	0.93
Intraclass Correlation Coefficient (95% CI)	0.87 (0.71 to 0.95)	0.74 (0.39 to 0.91)	0.94 (0.86 to 0.98)	0.81 (0.57 to 0.93)
Total score	0.88 (0.75 to 0.95)
Mean (SD)	8.77 (4.01)	8.33 (3.44)	9.37 (4.76)	8.55 (3.45)
Total score	35.02 (12.27)

CI: Confidence Interval; SD: Standard Deviation. The reported factor coefficients are pattern coefficients obtained from the Promax-rotated solution. Because Promax is an oblique rotation, pattern coefficients are not constrained to the range of −1 to +1.

Significant correlations were observed between cognitive-behavioral response and physiological emotional response (r = 0.64, p < 0.05), physiological emotional response and out of control (r = 0.67, p < 0.05), and out of control and being neglected (r = 0.74, p < 0.001) (Fig. 2).

Fig. 2.

Factor structure model of the Birth Trauma Scale based on Confirmatory factor analyses (All factor loadings are significant at p < 0.05). CB: Cognitive Behavioral Response; PE: Physiological Emotional Response; OC: Out of Control; BN: Being Neglected. Numbers following each abbreviation indicate the corresponding item number within each factor.

In confirmatory factor analysis, with a Root Mean Square Error of Approximation of 0.078, Tucker-Lewis Index of 0.98, Comparative Fit Index of 0.98, and a normed chi-square of 3.9, the model demonstrated an excellent fit. Therefore, the factor structure can be confirmed (Table 3).

Table 3.

Confirmatory factor analyses fit Index of the birth trauma scale (n = 156).

Fit Indices	Fit
χ2	328.78
df	84
x2/df	3.9
P-value	< 0.001
CFI	0.98
TLI	0.98
RMSEA (90% CI)	0.078 (0.068, 0.088)

χ2: chi-square; df: degrees of freedom; χ2/df: normed chi-square; CFI: Comparative Fit Index; TLI: Tucker–Lewis index; RMSEA: root mean square error of approximation.

4.4. Hypothesis testing for construct validity

Hypothesis testing for construct validity provided additional evidence regarding the relationships between total Birth Trauma Scale scores and theoretically related constructs. Higher Birth Trauma Scale scores were significantly associated with negative overall childbirth experience (Pearson's r = −0.64, p < 0.001), higher postpartum-specific anxiety (Pearson's r = 0.379, p = 0.001), higher postpartum depressive symptoms (Spearman's ρ = 0.422, p < 0.001), and higher postpartum post-traumatic stress disorder symptoms (Spearman's ρ = 0.447, p < 0.001). The direction of these associations was consistent with the theoretically expected relationships and provided supporting evidence for the construct validity of the Persian Birth Trauma Scale.

5. Discussion

This study evaluated the psychometric properties of the Persian version of the Birth Trauma Scale among Iranian postpartum women. The findings supported the validity and reliability of the Persian Birth Trauma Scale. Face and content validity were satisfactory, and exploratory and confirmatory factor analyses supported a four-factor structure corresponding to the dimensions of Being Neglected, Out of Control, Physiological-Emotional Response, and Cognitive-Behavioral Response. Reliability was also supported by internal consistency and test–retest assessment. Overall, these findings indicate that the multidimensional structure of psychological birth trauma proposed in the original Birth Trauma Scale is generally applicable in the Iranian context.

Regarding reliability, the Persian Birth Trauma Scale demonstrated strong internal consistency, with a Cronbach's alpha coefficient of 0.91. This finding is comparable to the original Birth Trauma Scale developed by Zhang et al. (2023), in which Cronbach's alpha was 0.874 for the total scale and ranged from 0.804 to 0.904 across the four dimensions. The test–retest reliability of the Persian version was also satisfactory, with an ICC of 0.88 (95% CI: 0.75–0.95). These findings suggest that the Persian Birth Trauma Scale provides sufficiently consistent and stable scores for the assessment of psychological birth trauma among postpartum women.

The structural validity findings generally supported the factor structure of the original Birth Trauma Scale. Exploratory factor analysis identified four factors that together explained 59% of the total variance, compared with 66.724% in the original Chinese validation study (Zhang et al., 2023). Nevertheless, the same four conceptual dimensions—Being Neglected, Out of Control, Physiological-Emotional Response, and Cognitive-Behavioral Response—were retained in the Persian version. Confirmatory factor analysis further supported this structure, demonstrating an acceptable model fit (Root Mean Square Error of Approximation = 0.078, Comparative Fit Index = 0.98, Tucker–Lewis Index = 0.98, normed chi-square= 3.9). Thus, despite the lower proportion of explained variance in the Iranian sample, the overall dimensional structure of the original Birth Trauma Scale was reproduced.

The difference in explained variance between the Iranian and original Chinese samples may reflect cultural and healthcare-related differences in the interpretation and relative salience of childbirth experiences. Psychological birth trauma is inherently subjective, and perceptions of neglect, emotional support, autonomy, communication with healthcare professionals, and involvement in decision-making may be influenced by social norms and the organization of maternity care. Consequently, an experience interpreted as inadequate support, loss of control, or neglect may not carry precisely the same meaning or psychological weight across cultural settings. Similarly, cultural norms concerning the expression, recognition, and reporting of fear and emotional distress may influence how women interpret and respond to items assessing physiological-emotional and cognitive-behavioral reactions. The preservation of the same four dimensions in the Persian Birth Trauma Scale therefore suggests conceptual similarity with the original instrument, whereas the difference in explained variance may indicate variation in the relative contribution of these dimensions within the Iranian context.

The first dimension, Being Neglected, includes four items addressing experiences such as not being taken seriously by healthcare professionals, inadequate emotional support from family, ineffective communication with healthcare providers, and insufficient explanations and information about the childbirth process (Zhang et al., 2023). The retention of this dimension in the Persian version supports the relevance of interpersonal care, communication, and perceived support to Iranian women's experiences of psychological birth trauma. Previous research has shown that perceived neglect during childbirth may contribute to feelings of loneliness, helplessness, anger, and psychological distress (Beck et al., 2004; Abdollahpour and Motaghi, 2019). However, perceptions of adequate support, respectful communication, and appropriate involvement of healthcare professionals and family may vary according to cultural expectations and maternity-care practices. Therefore, although the underlying constructs of perceived neglect was preserved, the psychological importance assigned to individual experiences within this dimension may differ between cultural settings.

The second dimension, Out of Control, includes three items focusing on feelings of helplessness, lack of autonomy, and loss of control during childbirth (Zhang et al., 2023). This factor was also reproduced in the Iranian sample, suggesting that perceived control represents an important component of traumatic childbirth experiences across the two cultural contexts. Loss of control may arise from difficulty coping with pain, unexpected events or interventions during childbirth, or limited involvement in treatment and childbirth-related decisions. Previous studies have identified low perceived control and exclusion from decision-making as important features of traumatic childbirth experiences (Reed et al., 2017; Renbarger et al., 2022). Nevertheless, expectations regarding autonomy and participation in healthcare decision-making can differ across social and healthcare contexts. Consequently, the meaning or relative importance assigned to individual items concerning control and autonomy may not be identical across populations, even when the broader factor remains stable.

The third dimension, Physiological-Emotional Response, represented the largest proportion of explained variance in the Persian exploratory factor analysis (20%). This dimension reflects women's intense physiological and emotional reactions associated with traumatic childbirth, including fear, anxiety, and other physical manifestations of distress (Zhang et al., 2023). Such reactions represent an important subjective component of traumatic childbirth and may occur even in the absence of severe obstetric complications. Previous studies have described intense physiological and emotional responses among women who experience childbirth as traumatic (Ayers et al., 2018; Renbarger et al., 2022). At the same time, cultural norms regarding the expression, recognition, and reporting of fear and emotional distress may influence responses to items within this dimension. The prominence of the Physiological-Emotional Response factor in the Iranian sample therefore highlights the importance of considering women's subjective emotional and physiological experiences rather than defining birth trauma solely according to objective obstetric events.

The fourth dimension, Cognitive-Behavioral Response, includes four items reflecting women's cognitive and behavioral reactions following childbirth, including negative interpretations, attribution of responsibility, and behavioral changes associated with the traumatic experience (Zhang et al., 2023). Cognitive and behavioral responses to traumatic childbirth may be influenced by personal beliefs as well as cultural interpretations of adverse experiences. For example, fatalistic interpretations, attribution of responsibility to oneself or others, avoidance, and persistent negative memories have been described following traumatic childbirth (Ayers et al., 2007; Taghizadeh et al., 2014). Such responses may influence women's subsequent adjustment, relationships, and attitudes toward future childbirth. The retention of this factor in the Persian version suggests that post-event cognitive and behavioral responses are also relevant to Iranian postpartum women, although their specific interpretation and expression may be shaped by social and cultural beliefs.

Taken together, the cross-cultural findings are notable because the Persian version retained all four dimensions of the original Birth Trauma Scale despite being evaluated in a different linguistic, cultural, and healthcare context. The translation and cultural adaptation process included forward and back translation, evaluation of conceptual and semantic equivalence, expert assessment of cultural appropriateness, and evaluation of comprehensibility among postpartum women. No dimension was removed or replaced during the validation process. Nevertheless, differences in explained variance and in the relative contribution of the four factors indicate that complete measurement equivalence between the Iranian and original populations should not be assumed solely on the basis of a similar factor structure. To our knowledge, published cross-cultural validation evidence for the same 15-item Birth Trauma Scale developed by Zhang et al. (2023) in populations outside its original Chinese context remains limited. Therefore, direct comparison of the Persian Birth Trauma Scale with independently validated versions of the same instrument in additional cultural settings is currently restricted. Future studies evaluating the Birth Trauma Scale in diverse linguistic and cultural populations and conducting cross-cultural measurement invariance analyses would be valuable for determining whether individual items and the four dimensions function equivalently across populations.

The observed associations between total Birth Trauma Scale scores and theoretically related postpartum outcomes provided additional support for the construct validity of the Persian Birth Trauma Scale. Higher birth trauma scores were associated with greater postpartum depressive symptoms, post-traumatic stress disorder symptoms, and postpartum-specific anxiety, as well as less positive childbirth experiences. The direction of these associations was consistent with the theoretical expectation that greater psychological birth trauma would be accompanied by greater postpartum psychological distress and more negative perceptions of childbirth. In particular, the associations with established measures of postpartum depression and post-traumatic stress disorder symptoms provide evidence that Birth Trauma Scale scores are meaningfully related to relevant postpartum psychological outcomes. However, these associations should not be interpreted as establishing criterion or diagnostic validity, because the Birth Trauma Scale was not evaluated against an independent clinical or diagnostic reference standard for psychological birth trauma. Moreover, convergent validity with another specifically established measure of birth trauma, such as the City Birth Trauma Scale, and discriminant validity using theoretically distinct constructs were not directly evaluated. Future studies should therefore examine convergent and discriminant validity using appropriate external measures and evaluate criterion-related and predictive validity using clinical assessments and longitudinal designs. Such evidence will be particularly important before establishing clinical cut-off scores or using the Persian Birth Trauma Scale for individual-level screening or clinical decision-making.

From a clinical perspective, the Persian Birth Trauma Scale provides a structured means of assessing multiple dimensions of women's psychological experiences of childbirth, including perceived neglect, loss of control, physiological-emotional responses, and cognitive-behavioral responses. Its use in postpartum care may assist midwives and other maternal healthcare professionals in recognizing women reporting substantial birth-related psychological distress who may benefit from further clinical assessment and appropriate psychological or supportive care. The multidimensional nature of the scale may also help healthcare professionals identify which aspects of the childbirth experience are particularly distressing for an individual woman and may therefore warrant further attention. Importantly, however, the Birth Trauma Scale assesses psychological birth trauma rather than establishing a psychiatric diagnosis and should complement rather than replace comprehensive clinical assessment or diagnostic instruments for conditions such as childbirth-related post-traumatic stress disorder. In the absence of an established clinical cut-off for the Persian version, scores should not be interpreted as providing a definitive diagnosis of psychological birth trauma.

The Persian Birth Trauma Scale may additionally be useful in research and quality-improvement settings. Its multidimensional structure provides an opportunity to investigate which aspects of the childbirth experience are most strongly associated with subsequent maternal psychological outcomes and to examine relationships between psychological birth trauma and factors related to maternity care, family support, and postpartum adjustment. The instrument may also facilitate evaluation of birth-related psychological trauma across different Iranian populations and healthcare settings. Future research should examine its psychometric performance in larger and more geographically and culturally diverse Iranian samples, assess its responsiveness to changes over time and following supportive or psychological interventions, and investigate clinically meaningful thresholds where appropriate. Further studies comparing the Persian Birth Trauma Scale with established measures of related psychological constructs and clinical assessments are also needed to strengthen evidence regarding criterion-related validity and clinical utility. Cross-cultural measurement invariance studies would further clarify whether the scale can be used to make valid comparisons between Iranian women and populations in other cultural settings.

5.1. Strengths and limitations

An important strength of this study was the use of cluster random sampling among eligible postpartum women. In addition, this study represents the first psychometric evaluation of the Birth Trauma Scale in an Iranian population. Structural validity was examined using both exploratory and confirmatory factor analyses in independent subsamples, providing complementary evidence regarding the underlying structure of the Persian version. The translation and cultural adaptation procedures also considered conceptual, semantic, and cultural equivalence and incorporated evaluation by experts and members of the target population.

Several limitations should nevertheless be considered. First, participants were recruited from health centers in Tabriz, and the findings may therefore not be fully generalizable to postpartum women from other regions of Iran with different linguistic, sociocultural, or healthcare characteristics. Second, the recruitment procedure may have introduced self-selection bias. Eligible women were initially contacted by telephone, and participation was voluntary. Although in-person attendance at the health center was not mandatory and alternative participation methods, including telephone administration and questionnaire completion at home, were available, 311 of the 408 women confirmed as eligible ultimately participated in the study, corresponding to a participation rate of 76.0%. Detailed information regarding the childbirth experiences or psychological distress of non-participants was unavailable. Therefore, it cannot be determined whether women who declined participation or did not complete the participation process differed systematically from those who participated. In particular, women experiencing greater birth-related psychological distress may have been less willing to participate in research concerning their childbirth experience, potentially resulting in underrepresentation of women with more severe psychological birth trauma. This possibility should be considered when interpreting the findings and may further limit their generalizability. Third, the Birth Trauma Scale is a self-report instrument, and responses may be influenced by factors such as recall and social desirability.

Finally, although the significant associations between total Birth Trauma Scale scores and theoretically related constructs, including childbirth experience, postpartum post-traumatic stress disorder symptoms, postpartum depression, and postpartum-specific anxiety provided supporting evidence for construct validity, several aspects of validity require further investigation. Convergent validity with another specifically established measure of birth trauma, such as the City Birth Trauma Scale, and discriminant validity using theoretically distinct constructs were not directly evaluated. In addition, criterion validity against an independent clinical assessment or diagnostic reference standard was not established. Therefore, the present findings should not be interpreted as establishing the Birth Trauma Scale as a diagnostic instrument or supporting a clinical cut-off. Future studies should evaluate convergent and discriminant validity using appropriate external measures, criterion-related and predictive validity using clinical assessments and longitudinal designs, and clinically meaningful thresholds, responsiveness, and measurement invariance across different populations.

6. Conclusion

The Persian version of the Birth Trauma Scale demonstrated satisfactory validity and reliability for assessing psychological birth trauma among Iranian postpartum women. The findings supported the four-factor structure of the original instrument, comprising Being Neglected, Out of Control, Physiological-Emotional Response, and Cognitive-Behavioral Response. The Persian Birth Trauma Scale may provide a useful structured instrument for research and for assessing different dimensions of birth-related psychological distress in postpartum care. However, given that criterion validity and clinically meaningful cut-off values have not yet been established, the scale should not currently be used as a stand-alone diagnostic instrument. Further studies in diverse Iranian populations, including evaluation of criterion-related validity, responsiveness, clinical thresholds, and cross-cultural measurement invariance, are warranted to strengthen its clinical and research applications.

Ethics approval

The protocol for this study was registered in the Tabriz University of Medical Sciences in Iran and was approved by the ethics committee of the university with the code IR.TBZMED.REC.1402.945, which was performed under the ethical principles laid down in the seventh and current edition (2013) of the Declaration of Helsinki.

Informed consent

Written informed consent was obtained from all subjects and/or their legal guardian(s).

Funding

Tabriz University of Medical Sciences provided funding but it had no role in the design and conduct of the study and decision to this manuscript writing and submission.

CRediT authorship contribution statement

Minoo Ranjbar: Writing – original draft, Software, Data curation, Conceptualization. Mahnaz Shahnazi: Writing – review & editing, Supervision, Methodology, Conceptualization. Sakineh Mohammad-Alizadeh-Charandabi: Writing – review & editing, Supervision, Investigation, Conceptualization. Fatemeh Abbasalizadeh: Writing – review & editing, Visualization, Supervision, Methodology, Conceptualization. Ali Reza Shafiee: Writing – review & editing, Supervision, Methodology, Conceptualization. Mojgan Mirghafourvand: Writing – review & editing, Visualization, Validation, Supervision, Resources, Methodology, Conceptualization.

Declaration of competing interest

The authors declare no competing interests.

Data availability

The datasets used during the current study are available from the corresponding author on reasonable request.